Patent Description:
This application also claims priority from <CIT>.

The present disclosure generally relates to machine telematics, and more specifically to a method and a device for power-efficient detection of cranking voltage.

A telematics system may gather asset data using a telematics device. The telematics device may be integrated into or located onboard the asset. The asset may be a vehicle ("vehicular asset") or some stationary equipment. The telematics device may collect the asset data from the asset through a data connection with the asset. In the case of a vehicular asset, the telematics device may gather the asset data through an onboard diagnostic port (OBD). The gathered asset data may include engine revolutions-per-minute (RPM), battery voltage, fuel level, tire pressure, oil temperature, or any other asset data available through the diagnostic port. Additionally, the telematics device may gather sensor data pertaining to the asset via sensors on the telematics device. For example, the telematics device may have temperature and pressure sensors, inertial measurement units (IMU), optical sensors, and the like. Furthermore, the telematics device may gather location data pertaining to the asset from a location module on the telematics device. When the telematics device is coupled to the asset, the gathered sensor data and location data pertain to the asset. The gathered asset data, sensor data and location data may be received and recorded by a technical infrastructure of the telematics system, such as a telematics server, and used in the provision of fleet management tools, for telematics services, or for further data analysis. Patent publications <CIT>, <CIT>, <CIT>, and <CIT> discuss information that is useful for understanding the background of the invention.

Accordingly, the present invention discloses a method and a telematics device as set out in the appended claims. Briefly, a telematics device having a voltage drop detector and a switchable voltage monitor is provided. The voltage drop detector detects a drop in the battery voltage characteristic of cranking and notifies a controller. In response, the controller turns on a switchable voltage monitor to monitor the battery voltage during cranking and beyond. Advantageously, there is no drain on the vehicle's battery when the vehicle is off prior to cranking.

In one aspect of the present disclosure, there is provided a method in a telematics device coupled to a machine, the machine having an engine coupled to a starter motor powered by a battery of the machine. The method comprises detecting, by a voltage drop detector connected with the battery, a voltage drop in the battery voltage that is greater than a voltage drop threshold. In response to detecting the voltage drop, the method further comprises triggering, by the voltage drop detector, a cranking event on a controller of the telematics device. In response to the cranking event, the method further comprises switching on, by the controller, a switchable voltage monitor connected with the battery, wherein the voltage drop detector is configured to consume essentially no power except when the voltage drop in the battery voltage is greater than the voltage drop threshold. Advantageously, the switchable voltage monitor is only turned on when there is a change in the battery voltage characteristic of a cranking event. Thus draining the battery by the battery voltage is avoided.

The method may further comprise converting a voltage output by the switchable voltage monitor to a digital value representing a cranking voltage of the machine.

The voltage drop detector consumes no power except when the voltage drop in the battery voltage is greater than the voltage drop threshold. Advantageously, the voltage drop detector does not drain the battery since it is not consuming power all the time.

The switchable voltage monitor may consume no power when switched off. Advantageously, the switchable voltage monitor does not drain the battery when the vehicle is off and/or there is no cranking event.

The voltage drop threshold may be greater than or equal to a turn-on voltage of a transistor of the voltage drop detector. Advantageously, readily available components such as transistors are used to make the voltage drop detector.

Triggering the cranking event may comprise asserting a cranking event signal between the voltage drop detector and the controller.

Switching on the switchable voltage monitor may comprise asserting, by the controller, a voltage monitor enablement signal between the controller and the switchable voltage monitor.

Asserting the voltage monitor enablement signal may cause a transistor of the switchable voltage monitor to switch on thus connecting a voltage monitor of the switchable voltage monitor with the battery.

The method may further comprise transmitting the digital value representing the cranking voltage to a remote server. For example, the digital value representing the cranking voltage may be sent to a telematics server for analysis and/or storage.

Converting the voltage monitor output by the switchable voltage monitor to the digital value may comprise enabling, by the controller, a conversion at an analog-to-digital converter (ADC) coupled with the controller and connected with the voltage monitor output of the switchable voltage monitor. Advantageously, the ADC is not constantly performing a conversion of the voltage monitor output, but does so only under control of the controller and in response to a cranking event. As a result the ADC is not constantly consuming power and/or draining the battery.

The method further may comprise switching off the switchable voltage monitor in response to detecting that the machine has been turned off. Advantageously, when the machine has been turned off, the switchable voltage monitor is switched off to conserve battery power.

Switching off the switchable voltage monitor may comprise de-asserting a voltage monitor enablement signal.

De-asserting the voltage monitor enablement signal may cause a transistor of the switchable voltage monitor to turn off thus isolating a voltage monitor of the switchable voltage monitor from the battery. By isolating the voltage monitor from the battery, the voltage monitor does not drain any current from the battery.

The method may further comprise detecting, by the voltage drop detector, a rise in the battery voltage and cancelling, by the voltage drop detector, the cranking event. Advantageously, if the cranking is abandoned and the battery voltage rises, the voltage drop detector cancels the cranking event and the controller does not switch on the switchable voltage monitor thus saving battery power when there is no cranking voltage to monitor. Cancelling the cranking event may comprise de-asserting the cranking event signal.

The method may further comprise detecting that the engine is running, and keeping the switchable voltage monitor switched on in response to detecting that the engine is running. For example, if the engine starts running, the telematics device keeps the switchable voltage monitor switched on. As the engine is running, a generator such as an alternator is also running and there is no danger in draining the battery. Accordingly, keeping the switchable voltage monitor switched on ensures obtaining voltage values of the battery voltage in real-time.

The method may further comprise detecting that the engine is not running, and switching off the switchable voltage monitor in response to detecting that the engine is not running. For example, if the engine has not started after cranking is concluded, the telematics device may cause the switchable voltage monitor to be switched off so as not to drain the battery.

The method may further comprise switching off the switchable voltage monitor subsequent to converting the voltage monitor output. For example, once the ADC conversion is concluded, the controller may turn off the switchable voltage monitor. This may be the case where a single value of the cranking voltage is required.

The method may further comprise periodically switching on and switching off the switchable voltage monitor for obtaining a plurality of voltage monitor outputs. For example, the controller may periodically switch on the switchable voltage monitor, covert the voltage monitor output to a digital value, then switch off the switchable voltage monitor. In this embodiment, the telematics device samples the voltage monitor output periodically converting the sampled output voltages to digital values, but switches off the switchable voltage monitor periodically so it is not switched on all the time.

In another aspect of the present disclosure, there is provided a telematics device for coupling to a machine having an engine coupled to a starter motor powered by a battery of the machine. The telematics device comprises a controller, a network interface coupled to the controller, a voltage drop detector coupled to the controller and connectable with the battery, a switchable voltage monitor coupled to the controller, and connectable with the battery, and a memory coupled to the controller. The memory stores memory storing machine-executable programming instructions for execution by the controller. When the telematics device is coupled with a vehicle, the telematics device performs the steps of the previous method.

In yet another aspect of the present disclosure, there is provided a telematics device for coupling to a machine having an engine coupled to a starter motor powered by a battery of the machine. The telematics device comprises a controller, a network interface coupled to the controller, a voltage drop detector coupled to the controller and connectable with the battery, a switchable voltage monitor coupled to the controller, and connectable with the battery, and a memory coupled to the controller. The memory stores memory storing machine-executable programming instructions for execution by the controller. When the telematics device is coupled with a vehicle, the voltage drop detector is connected with the battery, the switchable voltage monitor is connected with the battery, and the voltage drop detector detects a voltage drop in a battery voltage of the battery that is greater than a voltage drop threshold. In response to detecting the voltage drop, the voltage drop detector triggers a cranking event on the controller. In response to the cranking event, the controller executes machine-executable programming instructions which switch on the switchable voltage monitor.

Exemplary non-limiting embodiments of the present invention are described with reference to the accompanying drawings in which:.

A large telematics system may collect data from a high number of assets, either directly or through telematic devices. A telematics device may refer to a self-contained device installed at an asset, or a telematics device that is integrated into the asset itself. In either case, it may be said that telematics data is being captured or gathered by the telematics device. <FIG> shows a high-level block diagram of a telematics system <NUM>. The telematics system <NUM> includes a telematics server <NUM>, (N) telematics devices shown as telematics device 200_1, telematics device 200_2. through telematics device 200_N ("telematics device <NUM>"), a network <NUM>, administration terminal <NUM>, and operator terminals 150_1, 150_2. through 150_N ("the operator terminals <NUM>"). <FIG> also shows a plurality of (N) assets named as asset 100_1, asset 100_2. asset 100_N ("asset <NUM>") coupled to the telematics device 200_1, telematics device 200_2. telematics device 200_N, respectively. Additionally, <FIG> shows a plurality of satellites 170_1, 170_2 and 170_3 ("the satellites <NUM>") in communication with the telematics devices <NUM> for facilitating navigation.

The assets <NUM> shown are in the form of vehicles. For example, the asset 100_1 is shown as a truck, which may be part of a fleet that delivers goods or provides services. The asset 100_2 is shown as a passenger car that typically runs on an internal combustion engine (ICE). The asset 100_3 is shown as an electric vehicle (EV). Other types of vehicles, which are not shown, are also contemplated in the various embodiments of the present disclosure, including but not limited to, farming vehicles, construction vehicles, military vehicles, and the like.

The telematics devices <NUM> are electronic devices which are coupled to assets <NUM> and configured to capture asset data from the assets <NUM>. For example, in <FIG> the telematics device 200_1 is coupled to the asset 100_1. Similarly, the telematics device 200_2 is coupled to the asset 100_2 and the telematics device 200_3 is coupled to the asset 100_3. The components of a telematics device <NUM> are explained in further detail with reference to <FIG>.

The network <NUM> may be a single network or a combination of networks such as a data cellular network, the Internet, and other network technologies. The network <NUM> may provide connectivity between the telematics devices <NUM> and the telematics server <NUM>, between the administration terminal <NUM> and the telematics server <NUM>, and between the operator terminals <NUM> and the telematics server <NUM>.

The telematics server <NUM> is an electronic device executing machine-executable programming instructions which enable the telematics server <NUM> to store and analyze telematics data. The telematics server <NUM> may be a single computer system or a cluster of computers. The telematics server <NUM> may be running an operating system such as Linux, Windows, Unix, or any other equivalent operating system. Alternatively, the telematics server <NUM> may be a software component hosted on a cloud service, such as Amazon Web Service (AWS). The telematics server <NUM> is connected to the network <NUM> and may receive telematics data from the telematics devices <NUM>. The telematics server <NUM> may have a plurality of software modules for performing data analysis and analytics on the telematics data to obtain useful asset information about the assets <NUM>. The telematics server <NUM> may be coupled to a telematics database <NUM> for storing telematics data and/or the results of the analytics which are related to the assets <NUM>. The asset information stored may include operator information about the operators <NUM> corresponding to the assets. The telematics server <NUM> may communicate the asset data and/or the operator information pertaining to an asset <NUM> to one or more of: the administration terminal <NUM>, and the operator terminal <NUM>.

The satellites <NUM> may be part of a global navigation satellite system (GNSS) and may provide location information to the telematics devices <NUM>. The location information may be processed by a location module on the telematics device <NUM> to provide location data indicating the location of the telematics device <NUM> (and hence the location of the asset <NUM> coupled thereto). A telematics device <NUM> that can periodically report an asset's location is often termed an "asset tracking device".

The administration terminal <NUM> is an electronic device, which may be used to connect to the telematics server <NUM> to retrieve data and analytics related to one or more assets <NUM> or to issue commands to one or more telematics device <NUM> via the telematics server <NUM>. The administration terminal <NUM> is shown as a laptop computer, but may also be a desktop computer, a tablet (not shown), or a smartphone. The administration terminal <NUM> may run a web browser or a custom application which allows retrieving data and analytics, pertaining to one or more assets <NUM>, from the telematics server <NUM> via a web interface of the telematics server <NUM>. The administration terminal <NUM> may also be used to issue commands to one or more telematics device <NUM> via the telematics server <NUM>. A fleet manager <NUM> may communicate with the telematics server <NUM> using the administration terminal <NUM>. In addition to retrieving data and analytics, the administration terminal <NUM> allows the fleet manager <NUM> to set alerts and geofences for keeping track of the assets <NUM>, receiving notifications of deliveries, and so on.

The operator terminals <NUM> are electronic devices, such as smartphones or tablets. The operator terminals <NUM> are used by operators <NUM> (for example, vehicle drivers) of the assets <NUM> to both track and configure the usage of the assets <NUM>. For example, as shown in <FIG>, the operator 10_1 has the operator terminal 150_1, the operator 10_2 has the operator terminal 150_2, and the operator 10_N has the operator terminal 150_N. Assuming the operators <NUM> all belong to a fleet of vehicles, each of the operators <NUM> may operate any of the assets <NUM>. For example, <FIG> shows that the operator 10_1 is associated with the asset 100_1, the operator 10_2 is associated with the asset 100_2, and the operator 10_N is associated with the asset 100_N. However, any operator <NUM> may operate any asset <NUM> within a particular group of assets, such as a fleet. The operator terminals <NUM> are in communication with the telematics server <NUM> over the network <NUM>. The operator terminals <NUM> may run at least one asset configuration application. The asset configuration application may be used by an operator <NUM> to inform the telematics server <NUM> that the asset <NUM> is currently being operated by the operator <NUM>. For example, the operator 10_2 may use an asset configuration application on the operator terminal 150_2 to indicate that the operator 10_2 is currently using the asset 100_2. The telematics server <NUM> updates the telematics database <NUM> to indicate that the asset 100_2 is currently associated with the operator 10_2. Additionally, the asset configuration application may be used to report information related to the operation duration of the vehicle, the number of stops made by the operator during their working shift, and so on. Furthermore, the asset configuration application may allow the operator to configure the telematics device <NUM> coupled to the asset <NUM> that the operator <NUM> is operating.

In operation, a telematics device <NUM> is coupled to an asset <NUM> to capture asset data. The asset data may be combined with location data obtained by the telematics device <NUM> from a location module in communication with the satellites <NUM> and/or sensor data gathered from sensors in the telematics device <NUM> or another device coupled to the telematics device <NUM>. The combined asset data, location data, and sensor data may be termed "telematics data. " The telematics device <NUM> sends the telematics data to the telematics server <NUM> over the network <NUM>. The telematics server <NUM> may process, aggregate, and analyze the telematics data to generate asset information pertaining to the assets <NUM> or to a fleet of assets. The telematics server <NUM> may store the telematics data and/or the generated asset information in the telematics database <NUM>. The administration terminal <NUM> may connect to the telematics server <NUM>, over the network <NUM>, to access the generated asset information. Alternatively, the telematics server <NUM> may push the generated asset information to the administration terminal <NUM>. Additionally, the operators <NUM>, using their operator terminals <NUM>, may indicate to the telematics server <NUM> which assets <NUM> they are associated with. The telematics server <NUM> updates the telematics database <NUM> accordingly to associate the operator <NUM> with the asset <NUM>. Furthermore, the telematics server <NUM> may provide additional analytics related to the operators <NUM> including work time, location, and operating parameters. For example, for vehicle assets, the telematics data may include turning, speeding, and braking information. The telematics server <NUM> can correlate the telematics data to the vehicle's driver by querying the telematics database <NUM>. A fleet manager <NUM> may use the administration terminal <NUM> to set alerts for certain activities pertaining to the assets <NUM>. When criteria for an alert is met, the telematics server <NUM> sends a message to the administration terminal <NUM> to notify a fleet manager <NUM>, and may optionally send alerts to the operator terminal <NUM> to notify an operator <NUM> of the alert. For example, a vehicle driver operating the vehicle outside of a service area or hours of service may receive an alert on their operator terminal <NUM>. A fleet manager <NUM> may also use the administration terminal <NUM> to configure a telematics device <NUM> by issuing commands thereto via the telematics server <NUM>. Alerts may also be sent to the telematics device <NUM> to generate an alert to the driver such as a beep, a displayed message, or an audio message.

Further details relating to the telematics device <NUM> and how it interfaces with an asset <NUM> are shown with reference to <FIG> depicts an asset <NUM> and a telematics device <NUM> coupled thereto. Selected relevant components of each of the asset <NUM> and the telematics device <NUM> are shown.

The asset <NUM> may have a plurality of electronic control units (ECUs). An ECU is an electronic module which interfaces with one or more sensors for gathering information from the asset <NUM>. For example, an engine coolant temperature (ECT) ECU may contain a temperature sensor and a controller for converting the measured temperature into digital data representative of the oil temperature. Similarly, a battery voltage ECU may contain a voltage sensor for measuring the voltage at the positive battery terminal and a controller for converting the measured voltage into digital data representative of the battery voltage. A vehicle may, for example, have around seventy ECUs. For simplicity, only a few of the ECUs <NUM> are depicted in <FIG>. For example, in the depicted embodiment the asset <NUM> has three ECUs shown as the ECU 110A, the ECU 110B, and the ECU 110C ("the ECUs <NUM>"). The ECU 110A, the ECU 110B, and the ECU 110C are shown to be interconnected via an asset communications bus. One example of an asset communications bus is a Controller Area Network (CAN) bus. For example, in <FIG> the ECUs <NUM> are interconnected using the CAN bus <NUM>. The ECUs <NUM> send and receive information to one another in CAN data frames by placing the information on the CAN bus <NUM>. When an ECU <NUM> places information on the CAN bus <NUM>, other ECUs <NUM> receive the information and may or may not consume or use that information. Different protocols may be used to exchange information between the ECUs over a CAN bus. For example, ECUs <NUM> in trucks and heavy vehicles use the Society of Automotive Engineering (SAE) J1939 protocol to exchange information over a CAN bus <NUM>. Most passenger vehicles use the SAE J1979 protocol, which is commonly known as On-Board Diagnostic (OBD) protocol to exchange information between ECUs <NUM> on their CAN bus <NUM>. In industrial automation, ECUs use a CANOpen protocol to exchange information over a CAN bus <NUM>. An asset <NUM> may allow access to information exchanged over the CAN bus <NUM> via an interface port <NUM>. For example, if the asset <NUM> is a passenger car, then the interface port <NUM> is most likely an OBD-II port. Data accessible through the interface port <NUM> is termed the asset data <NUM>. In some embodiments, the interface port <NUM> includes a power interface for providing electric power to a telematics device <NUM> connected thereto.

The telematics device <NUM> includes a controller device (controller <NUM>) coupled to a memory <NUM>, an interface layer <NUM> and a network interface <NUM>. The telematics device <NUM> also includes one or more sensors <NUM> and a location module <NUM> coupled to the interface layer <NUM>. The telematics device <NUM> may also contain some optional components, shown in dashed lines in <FIG>. For example, the telematics device <NUM> may contain one or more of: a near-field communications (NFC) module such as NFC module <NUM>, a short-range wireless communications module <NUM>, and a wired communications module such as a serial communications module <NUM>. In some embodiments (not shown), the telematics device <NUM> may have a dedicated power source or a battery. In other embodiments, the telematics device <NUM> may receive power directly from the asset <NUM>, via the interface port <NUM>. The telematics device <NUM> shown is an example. Some of the components shown in solid lines may also be optional and may be implemented in separate modules. For example, some telematics devices (not shown) may not have a location module <NUM> and may rely on an external location module for obtaining the location data <NUM>. Some telematics devices may not have any sensors <NUM> and may rely on external sensors for obtaining sensor data <NUM>.

The controller <NUM> may include one or any combination of a processor, microprocessor, microcontroller (MCU), central processing unit (CPU), processing core, state machine, logic gate array, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or similar, capable of executing, whether by software, hardware, firmware, or a combination of such, the actions performed by the controller <NUM> as described herein. The controller <NUM> may have an internal memory for storing machine-executable programming instructions to conduct the methods described herein.

The memory <NUM> may include read-only-memory (ROM), random access memory (RAM), flash memory, magnetic storage, optical storage, and similar, or any combination thereof, for storing machine-executable programming instructions and data to support the functionality described herein. The memory <NUM> is coupled to the controller <NUM> thus enabling the controller <NUM> to execute the machine-executable programming instructions stored in the memory <NUM> and to access the data stored therein. The memory <NUM> may contain machine-executable programming instructions, which when executed by the controller <NUM>, configures the telematics device <NUM> for receiving asset data <NUM> from the asset <NUM> via the asset interface <NUM>, and for receiving sensor data <NUM> from the sensors <NUM> and/or location data <NUM> from the location module <NUM> via the sensor interface <NUM>. The memory <NUM> may also contain machine-executable programming instructions for combining asset data <NUM>, sensor data <NUM> and location data <NUM> into telematics data <NUM>. Additionally, the memory <NUM> may further contain instructions which, when executed by the controller <NUM>, configures the telematics device <NUM> to transmit the telematics data <NUM> via the network interface <NUM> to a telematics server <NUM> over a network <NUM>. In some embodiments, the memory <NUM> only stores data, and the machine-executable programming instructions for conducting the aforementioned tasks are stored in an internal memory of the controller <NUM>.

The location module <NUM> may be a global positioning system (GPS) transceiver or another type of location determination peripheral that may use, for example, wireless network information for location determination. The location module <NUM> is coupled to the controller <NUM> and provides location data <NUM> thereto. The location data <NUM> may be in the form of a latitude and longitude, for example.

The sensors <NUM> may be one or more of: a temperature sensor, a pressure sensor, an optical sensor, a motion sensor such as an accelerometer, a gyroscope, or any other suitable sensor indicating a condition pertaining to the asset <NUM> to which the telematics device <NUM> is coupled. The sensors provide sensor data <NUM> to the controller <NUM> via the sensor interface <NUM>.

The interface layer <NUM> may include a sensor interface <NUM> and an asset interface <NUM>. The sensor interface <NUM> is configured for receiving the sensor data <NUM> from the sensors <NUM>. For example, the sensor interface <NUM> interfaces with the sensors <NUM> and receives the sensor data <NUM> therefrom. The asset interface <NUM> receives asset data <NUM> from the asset <NUM>. In the depicted embodiment, the asset interface <NUM> is coupled to the interface port <NUM> of the asset <NUM>. The asset data <NUM>, received at the telematics device <NUM>, from the asset <NUM> may be in the form of data messages, such as CAN data frames. The asset data <NUM> may describe one or more of any of: a property, a state, and an operating condition of the asset <NUM>. For example, where the asset <NUM> is a vehicle, the data may describe the speed at which the vehicle is traveling, a state of the vehicle (off, idle, or running), or an engine operating condition (e.g., engine oil temperature, engine revolutions-per-minutes (RPM), or a battery voltage). In addition to receiving the asset data <NUM>, in some embodiments the asset interface <NUM> may also receive power from the asset <NUM> via the interface port <NUM>. The interface layer <NUM> is coupled to the controller <NUM> and provides both the asset data <NUM> and the sensor data <NUM> to the controller <NUM>.

The network interface <NUM> may include a cellular modem, such as an LTE-M modem, CAT-M modem, other cellular modem, Wi-Fi modem, or any other communication device configured for communication via the network <NUM> with which to communicate with the telematics server <NUM>. The network interface <NUM> may be used to transmit telematics data <NUM> obtained from the asset <NUM> to the telematics server <NUM> for a telematics service or other purposes. The network interface <NUM> may also be used to receive instructions from the telematics server <NUM> for configuring the telematics device <NUM> in a certain mode and/or requesting a particular type of the asset data <NUM> from the asset <NUM>.

The NFC module <NUM> may be an NFC reader which can read information stored on an NFC tag. The NFC module <NUM> may be used to confirm the identity of the operator <NUM> by having the operator <NUM> tap an NFC tag onto the telematics device <NUM> such that the NFC tag is read by the NFC module <NUM>. The information read from the NFC tag may be included in the telematics data <NUM> sent by the telematics device <NUM> to the telematics server <NUM>.

The short-range wireless communications module <NUM> is a component intended for providing short-range wireless communication capability to the telematics device <NUM>. The short-range wireless communications module <NUM> may be a BluetoothTM. wireless fidelity (Wi-Fi), ZigbeeTM, or any other short-range wireless communications module. The short-range wireless communications module <NUM> allows other devices to communicate with the telematics device <NUM> over a short-range wireless network.

The serial communications module <NUM> is an example of a wired communications module. The serial communications module <NUM> is an electronic peripheral for providing serial wired communications to the telematics device <NUM>. For example, the serial communications module <NUM> may include a universal asynchronous receiver transmitter (UART) providing serial communications per the RS-<NUM> protocol. Alternatively, the serial communications module <NUM> may be a serial peripheral interface (SPI) bus, or an inter-integrated circuit (I2C) bus. As another example, the serial communications module <NUM> may be a universal serial bus (USB) transceiver.

In operation, an ECU <NUM>, such as the ECU 110A, the ECU 110B, or the ECU 110C communicates asset data over the CAN bus <NUM>. The asset data exchanged between the ECUs <NUM>, over the CAN bus <NUM> are accessible via the interface port <NUM> and may be retrieved as the asset data <NUM> by the telematics device <NUM>. The controller <NUM> of the telematics device <NUM> receives the asset data <NUM> via the asset interface <NUM>. The controller <NUM> may also receive sensor data <NUM> from the sensors <NUM> over the sensor interface <NUM>. Furthermore, the controller <NUM> may receive location data <NUM> from the location module <NUM>. The controller <NUM> combines the asset data <NUM> with the sensor data <NUM> and the location data <NUM> to obtain the telematics data <NUM>. The controller <NUM> transmits the telematics data <NUM> to the telematics server <NUM> over the network <NUM> via the network interface <NUM>. Optionally, an operator <NUM> may tap an NFC tag to the NFC module <NUM> to identify themself as the operator <NUM> of the asset <NUM>. Additionally, an external peripheral, such as a GPS receiver, may connect with the telematics device <NUM> via the short-range wireless communications module <NUM> or the serial communications module <NUM> for providing location information thereto. In some embodiments, the telematics device <NUM> may receive, via the network interface <NUM>, commands from the telematics server <NUM>. The received commands instruct the telematics device <NUM> to be configured in a particular way. For example, the received commands may configure the way in which the telematics device gathers asset data <NUM> from the asset <NUM> as will be described in further detail below.

The telematics data <NUM> which is composed of asset data <NUM> gathered from the asset <NUM> combined with the sensor data <NUM> and the location data <NUM> may be used to derive useful data and analytics, by the telematics server <NUM>. However, there are times when additional data, which is not provided by the asset <NUM>, the sensors <NUM> or the location module <NUM> may be needed. The telematics device <NUM> may have a limited number of sensors <NUM> such as accelerometers or gyroscopes providing limited information about the motion of the asset <NUM> on which the telematics device <NUM> is deployed. The location module <NUM> may provide location and direction information. However, in some cases, more information may be needed to derive useful data and analytics pertaining to the asset <NUM>. One example of information that is not typically provided by the telematics device <NUM> is video capture data. Another example of information that is not typically provided by the telematics device <NUM> is any proprietary signaling provided by devices which does not follow any of the standard protocols (OBD-II, J1939 or CANOpen). Some equipment may not have a CAN bus and may provide proprietary digital and/or analog signals. Examples of such devices include industrial equipment, winter maintenance equipment such as salt spreaders, farming equipment, and the like. Additionally, the telematics device <NUM> may not have an NFC module <NUM> or a short-range wireless communications module <NUM> thus limiting its connectivity capabilities.

To capture and provide information or services not provided by the asset <NUM> or the telematics device, to produce an output, or to perform an action not supported by the telematics device, the telematics device <NUM> may be modified to allow an input/output expander device ("I/O expander") to connect thereto, as shown in <FIG> shows a telematics device <NUM> coupled to an asset <NUM>. An I/O expander <NUM> is coupled to the telematics device <NUM>.

The asset <NUM> is similar to the asset <NUM> of <FIG> and therefore the internal components thereof are not shown in <FIG> for simplicity.

The telematics device <NUM> has a somewhat similar configuration as the telematics device <NUM> of <FIG>, but some of the optional components have been removed. Furthermore, the telematics device <NUM> adds an I/O expander interface <NUM> for interfacing with the I/O expander <NUM>. The I/O expander interface <NUM> is coupled to the controller <NUM> and may be configured for exchanging I/O expander data <NUM> with the I/O expander <NUM>.

The I/O expander <NUM> of <FIG> is an example I/O expander which is designed to provide additional connectivity options to a telematics device <NUM>, which has more limited features than the one shown in <FIG>. For example, the telematics device <NUM> shown in <FIG> does not have an NFC module, a short-range wireless communications module, or a serial communications module. Instead, the telematics device <NUM> has an I/O expander interface <NUM>.

The I/O expander <NUM> may be an input device configured to capture additional data such as video frames, audio frames, or proprietary signals and provide that data to the telematics device <NUM>. Alternatively, or additionally, the I/O expander <NUM> may be configured as an output device and may include a display for displaying information and/or an audio output device for broadcasting messages pertaining to the asset <NUM>.

An I/O expander <NUM>, which connects with the telematics device <NUM>, varies in complexity depending on the purpose thereof. <FIG> shows an I/O expander <NUM> containing several components which may or may not all be present in other I/O expanders. For example, the I/O expander <NUM> includes a controller <NUM>, an NFC module <NUM>, an output device <NUM>, a short-range communications module <NUM>, an image sensor <NUM>, a serial communications module <NUM>, an uplink interface <NUM> and a downlink interface <NUM>.

The controller <NUM> may be similar to the controller <NUM> in <FIG>. In some embodiments, the controller <NUM> is a microcontroller with versatile I/O capabilities. For example, the controller <NUM> may be a microcontroller which has a plurality of I/O ports such as general-purpose inputs and outputs (GPIOs), serial ports, analog inputs, and the like. In some embodiments, the controller <NUM> may have built-in persistent memory such as flash memory on which machine-executable programming instructions for conducting the functionality of the I/O expander <NUM> may be stored. In other embodiments, the controller <NUM> may be coupled to a persistent memory module (not shown) that contains the machine-executable programming instructions for conducting the functionality of the I/O expander <NUM>. The controller <NUM> may also have built-in volatile memory, such as random-access memory (RAM) for storing data. Alternatively, the I/O expander <NUM> may be connected to an external volatile memory for storing data.

The image sensor <NUM> may be a digital still camera or a digital video camera capable of capturing images. For example, the image sensor <NUM> may be a road-facing dashboard camera for monitoring the road ahead. In other examples, the image sensor <NUM> may be a driver-facing dashboard camera for identifying the operator <NUM> and/or their condition.

The uplink interface <NUM> is an electronic peripheral interface coupled to the controller <NUM> and is used to provide data exchange and/or power capabilities to the I/O expander <NUM>. The uplink interface <NUM> allows the I/O expander <NUM> to transmit and receive I/O expander data. The uplink interface <NUM> is configured to use the same protocol and signaling as the I/O expander interface <NUM> of the telematics device <NUM>. Accordingly, the I/O expander <NUM> may exchange the I/O expander data with the telematics device <NUM>. In some embodiments, the uplink interface <NUM> may also include power pins connected to corresponding power pins in the I/O expander interface <NUM>, thus allowing the I/O expander <NUM> to be powered via the telematics device <NUM>. In other embodiments (not shown), the I/O expander <NUM> may have its own power source instead of or in addition to the power provided by the telematics device <NUM> via the uplink interface <NUM>.

The downlink interface <NUM> is an electronic peripheral interface coupled to the uplink interface <NUM>. The downlink interface <NUM> is configured to interface with the uplink interface <NUM> of another I/O expander <NUM> (as will be described below). Allowing the uplink interface <NUM> to connect to the downlink interface <NUM> of another I/O expander allows the daisy chaining of I/O expanders.

In the above-mentioned figures, a telematics device is shown as a separate entity connected with a corresponding asset. The telematics device, however, may have its components integrated into the asset <NUM> at the time of manufacture of the asset <NUM>. This may be the case when the asset <NUM> is a connected car having an asset network interface. For example, with reference to <FIG>, there is shown an asset <NUM> with the components of a telematics device integrated therein, in accordance with embodiments of the present disclosure. The asset <NUM> is similar to the asset <NUM> but, being a connected asset such as a connected car, it has an asset network interface <NUM>. In the depicted embodiment, the controller <NUM> is directly connected to the asset communications bus, which is a CAN bus <NUM> and may directly obtain the asset data <NUM> therefrom. The sensors <NUM> and the location module <NUM> are also integrated into the asset <NUM> and provide the sensor data <NUM> and the location data <NUM> to the controller <NUM> as described above. The asset network interface <NUM> belongs to the asset <NUM> and may be used by the asset <NUM> to communicate with an original equipment manufacturer (OEM) server, to a roadside assistance server, or for other purposes. The controller <NUM> may utilize the asset network interface <NUM> for the transmission of telematics data <NUM> provided by the controller <NUM>. In order to support further not provided by the integrated peripherals such as the sensors <NUM> and the location module <NUM>, the asset has an I/O expander interface <NUM> coupled to the controller <NUM> so that an I/O expander <NUM> may be connected to the asset <NUM> therethrough. The asset <NUM> may have an interface port <NUM> for connecting other devices other than a telematics device <NUM>, such as a diagnostic tool including, but not limited to, an OBD-II reader device.

A telematics device <NUM> may capture asset data <NUM> via the interface port <NUM> of an asset <NUM> via one of two main methods. The first method is for the telematics device <NUM> to listen for information placed by the ECUs <NUM> on the asset communications bus. For example, for the CAN bus <NUM>, the ECUs <NUM> may place broadcast CAN frames on the CAN bus <NUM> that the telematics device <NUM> can capture over the interface port. The second method is for the telematics device <NUM> to explicitly request information from an ECU <NUM> using a request command.

A telematics device <NUM> deployed in an asset whether connected to an interface port <NUM> or integrated within the asset may be configured as an asset tracking device in that it tracks and reports the location of the asset at all times. However, a distinction is made between cases when the vehicle is on and in motion and when the vehicle is off, as will be described below.

While the vehicle is operational with the ignition turned on (or the electric motor of an EV is on), a telematics device <NUM> obtains and sends telematics data <NUM> to the telematics server <NUM> as described above. In order to report the location data <NUM> with a fine granularity (i.e., the location up to a few meters' accuracy), the location data <NUM> is reported to the telematics server <NUM> several times per second. For example, a vehicle travelling at <NUM>/h moves <NUM> meters per second. A vehicle moving at <NUM>/h moves <NUM> meters per second. Reporting the location data <NUM> along with other asset data <NUM> in real-time or near real-time, requires the telematics device <NUM> to be in a fully operational mode in which it gathers the asset data <NUM>, the sensor data <NUM> and the location data <NUM>, combines them into telematics data <NUM> and sends the telematics data <NUM> over the network interface <NUM>. The sensors <NUM>, the location module <NUM>, the interface module, and the network interface <NUM> all have to be powered up during the fully operational mode. The telematics device <NUM> obtains power from a power source of the asset <NUM>, such as the battery <NUM>. When the asset <NUM> is travelling, the engine <NUM> is running and the alternator <NUM> is charging the battery <NUM>.

When the vehicle is off (i.e., the ignition of an ICE vehicle is off or the EV is off), there is little to no asset data <NUM> generated by the ECUs <NUM>. This is the case, for example, when a vehicle is parked. As such, having the telematics device <NUM> in a fully operational mode with all the components such as the network interface <NUM> powered up all the time is unnecessary. Furthermore, as the engine <NUM> is not running, the alternator <NUM> is not charging the battery <NUM>. If the telematics device <NUM> is in a fully operational mode with many components powered on, the telematics device <NUM> may deplete the battery <NUM> over time as it continues to draw electric power therefrom.

One approach to reducing power consumed by the telematics device <NUM> when it is coupled to a vehicle asset which is not turned on is to implement a low-power scheme for the telematics device <NUM>. In a low-power scheme (or a power-saving scheme), the telematics device <NUM> enters a low-power mode (also known as sleep mode) and periodically wakes up. In other words, the telematics device <NUM> alternates between a sleep duration and a wake-up duration. During a sleep duration, the controller <NUM> of the telematics device <NUM> is running at a slower clock speed (i.e., is in a slow-clocking mode), and most of the peripherals such as the sensors <NUM>, location module <NUM>, and network interface <NUM> are powered off. During a wake-up duration, the controller <NUM> exits the slow-clocking mode and the peripherals are powered on. The telematics device <NUM> may report the location thereof as the location data <NUM>, which is part of the telematics data sent to the telematics server <NUM> during the wake-up duration. Since the vehicle is off, little to no asset data <NUM> is included in the telematics data <NUM> sent to the server. In this low-power scheme, the longer the sleep duration between two wakeup durations, the less the telematics server <NUM> receives updates about the location of the telematics device <NUM>, for example. However, a short sleep duration, which translates to more frequent wake-up durations consumes more electric power. Examples of a short sleep duration range from a few minutes to an hour. Examples of a long sleep duration range from a few hours to a few days. One combined approach is to use a short sleep duration until a long sleep duration threshold is met or exceeded, and then using a long sleep duration. This approach assumes that a vehicle that is not turned on for some time may be parked for an extended period of time and accordingly, receiving a frequent update about the vehicle's location is of less importance. The combined approach to a low-power scheme is explained further with reference to <FIG>.

<FIG> depicts a power-saving scheme 600A for operating a telematics device <NUM> when the asset <NUM>, which may be a vehicle, to which the telematics device <NUM> is coupled is turned off. A vehicle is off when an ignition is off for a vehicle with an internal combustion engine. For an electric vehicle (EV), a particular signal indicates whether the vehicle is on or off. In <FIG>, the horizontal axis represents time, while the vertical axis represents the electric power consumption of the telematics device <NUM>. At time <NUM>, the telematics device <NUM> detects that the vehicle to which the telematics device <NUM> is coupled is off and therefore the telematics device <NUM> is now drawing power from the battery <NUM>. The battery <NUM> may be drained if the telematics device <NUM> remains in fully operational mode. Accordingly, at time <NUM>, the telematics device <NUM> operates in sleep mode. The power consumption of the telematics device during the sleep mode is represented by the sleep power consumption level <NUM>. After a short sleep duration <NUM>, the telematics device <NUM> exits sleep mode and is fully operational for a wakeup duration <NUM>. During the wake-up duration <NUM>, the telematics device <NUM> reports the location data <NUM> to the telematics server <NUM> via the network interface <NUM>. During the wake-up duration, the telematics device <NUM> is consuming power at the full power level <NUM>. The telematics server <NUM> updates the location of the telematics device <NUM> and updates the miles travelled by the asset <NUM> associated with the telematics device <NUM>. The cycle comprising the short sleep duration <NUM> and the wake-up duration <NUM> is repeated until a time threshold since the start of the first sleep duration (i.e., time <NUM> in the figure) is exceeded. The time threshold may be termed the long sleep threshold <NUM>. If the long sleep threshold <NUM> is exceeded, the telematics device <NUM> switches to a long sleep duration <NUM>. As seen in <FIG>, past the long sleep threshold <NUM>, the telematics device sleeps for a long sleep duration <NUM> and wakes up for a wake-up duration <NUM>. An example of the short sleep duration may include <NUM> minutes, while an example of a long sleep duration may be <NUM> hours.

In the event that the asset is turned on, the telematics device <NUM> upon detecting an ignition signal or an EV on signal, will stop executing the power-saving scheme 600A and will be in the fully operational mode.

The power-saving scheme 600A thus has a first stage in which the telematics device <NUM> alternates between lower-power (sleep) mode and powered-up (wake-up) mode. Specifically, the power-saving scheme 600A has a first stage and a second stage. In the first stage the telematics device periodically sleeps for a first sleep duration and wakes up for a wake-up (powered-up) duration. In the second stage the telematics device periodically sleeps for a second sleep duration and wakes up for the wake-up duration. The second stage of the power-saving scheme 600A is triggered after the telematics device has been in the first stage for a duration greater than a long sleep duration threshold. The second sleep duration used in the second stage is longer than the first sleep duration used in the first stage of the power-saving scheme 600A. The telematics device <NUM> enters the second stage when the telematics device <NUM> has been in the first stage for more than a long sleep threshold <NUM>.

The power-saving scheme 600A proposed in <FIG> has a number of advantages. Initially, when an asset <NUM>, such as a vehicle is turned off, the telematics device <NUM> provides location updates on a frequent basis, such as every <NUM> minutes. The power-saving scheme 600A works for a vehicle which is parked for a short-term such as overnight and is going to be driven in the morning, or parked for a few days at the airport car park, for example. During that time, the vehicle's owner, or a fleet manager <NUM> can verify the location of the vehicle with a relatively short frequency. If a vehicle is parked for an extended period of time, then the sleep duration is switched to a long sleep duration, which further reduces the power consumption of the telematics device <NUM> and reduces the possibility of draining the asset's battery, such as the battery <NUM>. However, in some cases, sleep power consumption level <NUM> is still too high and may drain the vehicle battery. This may be because of some circuitry that needs to be on to capture certain events that may take place at any time. This will be explained further below.

Motor vehicles are equipped with batteries for providing electric energy to power the electrical components thereof. Typical vehicle batteries are either 12V batteries or 24V batteries. In this disclosure, mainly 12V batteries will be discussed, but it would be apparent to those of skill in the art that the methods described would be equally applicable to 24V batteries, and to batteries operating at other voltages. A vehicle battery needs to be charged such that it provides a battery output voltage which is in a battery operating voltage range. The battery operating voltage range has a lower battery output voltage limit and an upper battery output voltage limit. When the vehicle battery output voltage drops below the lower battery output voltage limit, the battery is considered undercharged and needs to be charged or it will not provide sufficient electrical power to the various electrical components. In the example of a 12V battery, the lower battery output voltage limit has been found to be <NUM>. When the vehicle battery output voltage rises above the upper battery output voltage limit, the vehicle battery is considered overcharged. An overcharged battery may deteriorate quickly and the vehicle battery output voltage, which is higher than the upper battery output voltage limit, may cause damage to some of the electrical components of the vehicle. In the example of a 12V battery, the upper battery output voltage limit has been found to be <NUM>. It is therefore generally desirable to keep the battery output voltage of a 12V vehicle battery between <NUM>. 2V and <NUM>.

Internal combustion engines need to be cranked to start their operation. Cranking an engine involves rotating the engine's crankshaft causing the pistons to move in a reciprocating manner within their corresponding cylinders. Rotating the crankshaft also causes intake valves to open letting air into the cylinders and causes an injection pump to inject fuel into the cylinders. For engines using carburetors, the intake valves let a fuel mixture of gasoline and air into the cylinders. For gasoline engines, cranking also causes the spark plugs to be activated thus igniting the fuel mixture and producing heat energy which displaces the pistons inside the cylinders. The displacement of the pistons in a reciprocating manner within the cylinders is converted to rotary motion by the crankshaft, and the engine is said to have been started. Cranking an engine is typically done by a starter motor mechanically coupled to the engine. The starter motor relies mainly on the vehicle battery to run during cranking.

Electricity generators used in vehicles are often referred to as alternators since they generate electricity having an alternating current (AC). The generated AC is then rectified and converted to direct current (DC) to power the vehicle's electrical components and to charge the vehicle's battery. An alternator is mechanically coupled to a vehicle's internal combustion engine and converts mechanical energy provided by the engine to electrical energy. In order to charge a vehicle battery to a particular output voltage, an alternator is configured to generally produce an alternator output voltage which is higher than the battery voltage by a charging voltage offset. Accordingly, an alternator has a lower alternator output voltage limit, which is greater than a corresponding lower battery output voltage limit by the charging voltage offset. Similarly, an alternator has an upper alternator output voltage limit which is greater than a corresponding upper battery output voltage limit by the charging voltage offset. By way of example, a charging voltage offset may be 1V. For a 12V battery, the lower battery output voltage limit is <NUM>. 2V and accordingly the lower alternator output voltage limit is <NUM>. 2V for an alternator configured to charge the battery by a charging voltage offset of 1V. Similarly, for the 12V battery, the upper battery output voltage limit is <NUM>. 6V and accordingly the upper alternator output voltage limit is <NUM>. 6V for an alternator configured to charge the battery by a charging offset of 1V.

An alternator is mechanically and rotationally coupled to a vehicle's engine in order to produce electricity. Similarly, a starter motor is mechanically and rotationally coupled to a vehicle's engine in order to crank the engine. With reference to <FIG>, there is shown an engine <NUM> mechanically coupled to both an alternator <NUM> and a starter motor <NUM>.

The engine <NUM> comprises a plurality of cylinders (now shown) in which a corresponding plurality of pistons are disposed and configured for reciprocating motion. The engine <NUM> also houses a crankshaft (not shown) mechanically coupled to the pistons. As known in the art, the reciprocating motion of the pistons are converted to rotational motion by the crankshaft. At one end of the crankshaft, there is a drive pulley <NUM> connected with the crankshaft and rotatable therewith. At the opposite end of the crankshaft, there is a flywheel <NUM> connected with the crankshaft and rotatable therewith. The flywheel <NUM> may be in the form of a gear and have a plurality of teeth.

An alternator <NUM> is disposed alongside the engine <NUM> and rotationally coupled thereto. The alternator <NUM> may be affixed to the engine block or to any part of the vehicle chassis. The alternator <NUM> includes an alternator pulley <NUM> connected to and rotatable with an alternator shaft. The alternator pulley <NUM> is rotationally coupled to the drive pulley <NUM>, typically by an alternator belt <NUM>. Accordingly, the alternator shaft rotates with the rotation of the engine crankshaft.

A starter motor <NUM> is disposed alongside the engine <NUM>. The starter motor <NUM> has a starter motor shaft <NUM> which provides rotational motion when electric power is provided to the starter motor <NUM>. A starter motor pinion gear <NUM> is connected to the starter motor shaft <NUM> and is rotatable therewith. A starter motor solenoid <NUM> allows extending and retracting the starter motor shaft <NUM>. To start the engine <NUM>, the starter motor solenoid <NUM> extends the starter motor shaft <NUM> until the starter motor pinion gear <NUM> engages with the flywheel <NUM> and rotates the engine's crankshaft. Once the engine has started, the starter motor solenoid <NUM> retracts the starter motor shaft <NUM> so that the starter motor pinion gear <NUM> disengages from the flywheel <NUM>.

When the engine <NUM> is off and is not being cranked (started), the crankshaft is not rotating and accordingly the drive pulley <NUM> is not rotating. As a result, the alternator pulley <NUM> is also not rotating and no electric power is generated by the alternator <NUM>. Similarly, no power is applied to the starter motor <NUM> and hence the starter motor pinion gear <NUM> does not rotate. Additionally, the starter motor shaft <NUM> is in retracted mode towards the starter motor <NUM> and the starter motor pinion gear <NUM> is not engaged with the flywheel <NUM>.

When the engine <NUM> is cranked (started), for example by a user turning a key in an ignition or actuating a push button ignition switch, electric power is applied from the vehicle's battery to the starter motor <NUM> including the starter motor solenoid <NUM>. In response to receiving electric power, the solenoid extends the starter motor shaft <NUM> until the teeth of the starter motor pinion gear <NUM> engage with the teeth of the flywheel <NUM>, as shown in dotted lines in the figure. Additionally, the starter motor <NUM> rotates the starter motor shaft <NUM> thus rotating the starter motor pinion gear <NUM> therewith. Since the flywheel <NUM> is engaged with the starter motor pinion gear <NUM>, the flywheel <NUM> rotates in the opposite direction to that of the starter motor pinion gear <NUM>. The crankshaft rotates with the flywheel <NUM>. As discussed above, the rotation of the crankshaft causes the engine to start. The drive pulley <NUM> rotates with the crankshaft. Since the alternator pulley <NUM> is rotationally coupled to the drive pulley <NUM> by the alternator belt <NUM>, the alternator pulley <NUM> also rotates and the alternator <NUM> generates some electricity.

When the engine <NUM> is running, the starter motor <NUM> is turned off. Additionally, the starter motor solenoid <NUM> retracts the starter motor shaft <NUM> such that the starter motor pinion gear <NUM> is disengaged from the flywheel <NUM>. As the engine is running, the drive pulley <NUM> is rotating by the action of the mechanical rotational motion produced by the engine <NUM>. The alternator <NUM> rotates with the engine <NUM> and produces electricity to power the electrical components of the vehicle.

The structure and operation of an alternator <NUM> are known in the art. For illustration, <FIG> shows a high-level block diagram of an alternator <NUM> identifying its principal components. An alternator <NUM> includes a rotor <NUM>, a stator <NUM>, an alternator housing <NUM>, a rectifier <NUM>, and a regulator <NUM>.

The rotor <NUM> is disposed on a shaft and rotatable therewith. The rotor <NUM> features an electromagnet (not shown) which is powered by the vehicle's battery and/or electric power generated by the alternator <NUM> itself. The power of the electromagnet affects the alternator output voltage. The higher the power of the electromagnet, the higher the alternator output voltage for the same rotational speed of the rotor shaft. Conversely, the lower the power of the electromagnet, the lower the alternator output voltage for the same rotational speed of the rotor shaft.

The stator <NUM> is circumferentially disposed inside the alternator housing <NUM> encompassing the rotor <NUM>. The stator <NUM> is comprised of a plurality of coils typically connected in a star configuration, as known in the art. The coils have terminals at which the generated AC is provided.

The rectifier <NUM> converts the generated AC provided at the terminals of the coils into DC. In some example embodiments, the rectifier is comprised of a plurality of diodes, and at least one capacitor as known in the art. For a typical <NUM>-phase alternator, there are at least <NUM> diodes.

The regulator <NUM> detects the alternator output voltage and ensures that it remains above the lower alternator output voltage limit and below the upper alternator output voltage limit. As shown the regulator <NUM> checks the battery output voltage and the alternator output voltage. As discussed above, the alternator output voltage is generally higher than the battery output voltage by a charging voltage offset. The regulator <NUM> determines the desired alternator output voltage based on the battery output voltage. If the alternator output voltage is different from the desired alternator output voltage, the regulator controls the power provided to the electromagnet of the rotor in order to maintain the alternator output voltage between the lower alternator output voltage limit and the upper alternator output voltage limit.

Rotating the alternator pulley <NUM> causes the rotor <NUM> to rotate with respect to the stator <NUM> and induce electricity in the stator <NUM>. The generated electricity is in the form of an alternating current (AC) which is provided at the stator terminals (not shown). The rectifier <NUM> converts the generated AC to direct current (DC) output. The DC output may be provided to charge the vehicle battery, power the electromagnet of the rotor <NUM>, and power the electrical components of the vehicle while the engine <NUM> is running.

The regulator <NUM> determines the desired alternator output voltage based on the battery operating voltage range. The regulator <NUM> then compares the alternator output voltage, provided thereto by the rectifier, as shown, with the desired alternator output voltage. Based on the comparison, the regulator may increase or decrease the electric power provided to the electromagnet of the rotor <NUM>. For example, for a 12V battery, the alternator output voltage needs to be between <NUM>. 2V and <NUM>. If the alternator output voltage was at 14V, then the alternator is overcharging the battery. The regulator <NUM> reduces the power provided to the electromagnet of the rotor <NUM>. As a result, the alternator output voltage is reduced. This is repeated until the alternator output voltage is at most at the upper alternator output voltage limit of <NUM>. Conversely, if the alternator output voltage is below <NUM>. 2V, the regulator <NUM> increases the electric power provided to the rotor <NUM>. As a result, the alternator output voltage is increased (for the same alternator shaft rotational speed), thus increasing the alternator output voltage. This is repeated until the alternator output voltage is at least at the lower alternator output voltage limit.

The electrical connections between the engine <NUM>, the starter motor <NUM> and the alternator <NUM> are shown in <FIG>.

<FIG> depict a simplified schematic of a vehicle's electric subsystems including a battery <NUM>, a starter motor <NUM>, an alternator <NUM>, a voltage-sensing device <NUM>, and an electrical component <NUM> shown as a light bulb. The battery <NUM> may be a lead acid battery or any other suitable type of battery used in vehicles. The battery <NUM> has a positive battery terminal <NUM> connected to the electrical component <NUM>, to the starter motor <NUM> and to the alternator <NUM>. The battery <NUM> also has a negative terminal <NUM> connected to the ground (i.e., the vehicle's metal chassis). The starter motor <NUM> is connected to the positive battery terminal <NUM> and to the ground. The alternator is connected to the positive battery terminal <NUM> and to the ground. The electrical component <NUM> may be any one of vehicle lights, gauges, air conditioner or entertainment system. The voltage-sensing device <NUM> is connected to the positive battery terminal <NUM> and the alternator output. The voltage measuring device may be a voltmeter, galvanometer, analog-to-digital converter (ADC), or any other suitable device that can measure voltage.

Turning first to <FIG>. In this figure, the engine <NUM> is in off mode. In other words, the engine <NUM> is neither running nor being cranked. Accordingly, the alternator <NUM> is not rotating and is not producing any electric power. The only source of electricity in the vehicle is the battery <NUM>. Thickened black lines in <FIG> show current flow between the battery <NUM> and the electrical component <NUM>. Since the battery <NUM> provides electric power to the electrical component <NUM> and is not being charged. The voltage measured by the voltage-sensing device <NUM> is the voltage of the battery <NUM> only. In the off mode, and in the presence of an electrical component <NUM> which is turned on, the battery <NUM> is drained after some time. The time to drain the battery <NUM> depends on the load of the electrical component <NUM> and the capacity of the battery <NUM>.

When a vehicle is started by a driver, for example by activating an ignition key, the engine <NUM>, starter motor <NUM> and alternator <NUM> are said to be in a cranking state or undergoing a cranking event. With reference to <FIG>, the diagram shows the same vehicle's electric subsystems of <FIG>. <FIG> also shows the current flowing as solid black lines. During a cranking event, the battery <NUM> provides power to the starter motor <NUM> as indicated by the solid line between the positive battery terminal <NUM> and the starter motor <NUM>. As the starter motor <NUM> is activated and engages the flywheel <NUM> as discussed above, the crankshaft of the engine rotates. As the alternator <NUM> is mechanically coupled to the crankshaft, the alternator shaft also rotates, and the alternator <NUM> starts generating some electricity. During cranking any electrical component <NUM> which is turned on consumes electric power from both the battery <NUM> and/or the alternator <NUM> depending on electric load of the electrical component <NUM>. The voltage measured at the positive battery terminal <NUM>, by the voltage-sensing device <NUM>, during cranking is termed the "cranking voltage". The cranking voltage fluctuates as the starter motor <NUM> starts and as the alternator <NUM> starts generating electricity. As discussed below, there is a point at which the cranking voltage is at a minimum value termed the "minimum cranking voltage" and another point at which the cranking voltage is at a maximum value termed the "maximum cranking voltage".

When the engine <NUM> starts, the cranking event is terminated and the starter motor <NUM> is both disengaged from the engine <NUM> and is no longer powered up. This is illustrated in <FIG>. After cranking is terminated, the voltage measured at the positive battery terminal <NUM>, by the voltage-sensing device <NUM>, is termed the "device voltage". As shown in <FIG>, there are solid black lines between the alternator <NUM> and the positive battery terminal <NUM> as well as between the positive battery terminal <NUM> and the electrical component <NUM> indicating that the electrical components <NUM> may be consuming electric power from both the alternator <NUM> and the battery <NUM>.

With reference to <FIG>, there is shown a graph depicting voltage measured at the positive battery terminal (to which the output of the alternator is connected) during and after a cranking event. The horizontal axis represents time, while the vertical axis represents the voltage measured at the positive battery terminal <NUM>. Before the cranking event, the measured voltage was around <NUM>. This represents the voltage at the positive battery terminal <NUM> with the alternator <NUM> not generating any electrical power. At time <NUM>, the cranking event starts. The first cranking voltage <NUM> is unchanged and is around <NUM>. As the starter motor <NUM> draws a large amount of current from the vehicle battery in order to start, the battery output voltage drops significantly. As discussed, the output voltage of the battery during a cranking event is considered a cranking voltage. As can be seen, the cranking voltage drops until it is at a minimum cranking voltage <NUM> (which is around <NUM>. 8V approximately). As the starter motor <NUM> starts rotating and gains momentum, the current drawn by the starter motor <NUM> drops and accordingly the cranking voltage rises. Additionally, as the starter motor <NUM> rotates at a faster speed, so does the crankshaft of the engine, and so does the alternator shaft. As a result, the alternator <NUM> starts producing electricity, and the cranking voltage rises. As shown between the time <NUM> and the time <NUM>.

At the time <NUM>, the cranking voltage reaches a maximum cranking voltage <NUM>. Once the engine has fully started, cranking is stopped, and the starter motor <NUM> is disengaged from the engine both electrically and mechanically. At this point, the voltage measured at the positive battery terminal <NUM> is the device voltage. The first device voltage <NUM> has the value of approximately <NUM>. At this point, the regulator <NUM> may increase the power provided to the electromagnet of the rotor <NUM> to bring the alternator output voltage to <NUM>. 6V so that it is higher by 1V than the battery output voltage, which was measured to be <NUM>. 6V before the cranking event. The device voltage reaches a maximum device voltage <NUM> at a time <NUM>.

Capturing the cranking voltage in real-time and recording voltage value during cranking can later give insights into the characteristics of the battery and/or the charging system. As such, the telematics device <NUM> needs to have a device for reading voltage at the positive battery terminal <NUM> during the cranking stage. In this disclosure, a device for reading voltage at the positive battery terminal <NUM> is termed a battery monitor.

With reference to <FIG>, there is shown a telematics device <NUM> comprising a controller <NUM>, a memory <NUM>, an analog-to-digital converter (ADC) in the form of ADC <NUM>, a voltage monitor <NUM>, and a load dump <NUM>.

The controller <NUM> and the memory <NUM> are similar to the controller <NUM>, and the memory <NUM> discussed above. Similarly, the network interface <NUM> is similar to the network interface <NUM>.

The load dump <NUM> provides protection against voltage/power surges at the positive battery terminal <NUM> thus protecting the electronic components of the telematics device <NUM>. A load dump is known in the art. By way of example only, the load dump <NUM> may limit voltage surges coming from the battery terminal to 60V (when in some cases they may be over 100V). The output of the load dump <NUM> is the power supply line 12V_PROT and is labeled as such to indicate that there is overload protection preventing voltage surges thereon. The 12V_PROT is thus a power supply line that is guaranteed to never exceed a voltage limit, such as 60V. Electronic components of the telematics device <NUM> are rated higher than the voltage limit and are thus guaranteed not to be damaged even if a higher voltage surge occurs on the positive battery terminal <NUM>. For example, the electronic components of the telematics device <NUM> may be rated for 80V and are thus not damaged even if the voltage on the power supply line 12V_PROT line reaches 60V.

The voltage monitor <NUM> is a device that provides an output signal representative of a voltage such as the battery voltage. In some embodiments, the voltage monitor <NUM> is a passive device which is connected to the positive battery terminal <NUM> via the load dump <NUM> and provides an output signal representative of the battery voltage. The output signal of the voltage monitor <NUM> is an analog voltage on the voltage monitor output <NUM>. The analog voltage represents the voltage at the positive battery terminal <NUM>, but may be scaled as will be discussed below.

One possible implementation of the voltage monitor <NUM> is shown in <FIG>. The voltage monitor <NUM> of <FIG> is a potential divider (a. "resistor divider" or "voltage divider") consisting of a first resistor R5 and a second resistor R6. The first resistor (R5) is disposed between the power supply line (12V_PROT) and the voltage monitor output <NUM>. The second resistor is disposed between the voltage monitor output <NUM> and the ground (GND). In the depicted embodiment, the first resistor R5 is <NUM> and the second resistor R6 is <NUM>. The voltage measured at <NUM> is determined by the formula: <MAT> Or <MAT>.

Accordingly, once the value of the voltage of the voltage monitor output <NUM> is known, it may be scaled up (in this case by multiplying by <NUM>) to obtain the value of the battery voltage as measured at the power supply line 12V_PROT, which represents the cranking voltage during cranking. Turning back to <FIG>, the ADC <NUM> is an analog to digital converter that converts the analog voltage of the voltage monitor output <NUM> to a digital value <NUM> representing the voltage monitor output <NUM> that is provided to the controller <NUM>. In some embodiments, the ADC <NUM> is an integral component of the controller <NUM> even though it is shown here as a separate block for clarity.

In operation, during cranking the voltage monitor <NUM> detects variations in the battery voltage at the positive battery terminal <NUM> of the vehicle battery, and provides a voltage monitor output <NUM> to the ADC <NUM>. The ADC <NUM> converts the analog voltage of the voltage monitor output <NUM> to a digital value <NUM> representative of the cranking voltage that is readable by the controller <NUM>. As discussed above, in some embodiments the analog voltage of the voltage monitor output <NUM> has been scaled by the voltage monitor <NUM>, as a result of passing through a voltage divider. In such cases, the controller <NUM> scales back the digital value <NUM> provided by the ADC <NUM> to obtain a true value of the battery voltage during cranking, i.e., a cranking voltage. The controller <NUM> sends the scaled digital value <NUM> of the cranking voltage to a remote server, such as the telematics server <NUM>, over the network interface <NUM>.

In some embodiments, the controller <NUM> repeatedly reads the digital value <NUM> corresponding to the voltage monitor output <NUM>, scales the digital value <NUM> and sends over a scaled digital value representing the battery voltage to a remote device such as the telematics server <NUM> over the network interface. In some embodiments, the telematics device <NUM> buffers a plurality of scaled digital values and sends them together to the telematics server <NUM>.

The telematics server <NUM> receives the scaled digital values representing the battery voltage and constructs a graph, such as the graph of <FIG> and/or identify significant events such as the minimum cranking voltage <NUM>, the maximum cranking voltage <NUM> and the first device voltage <NUM>.

Since a vehicle's engine may be started (i.e., cranked) at any time, the voltage monitor <NUM> needs to be connected to the positive battery terminal <NUM> or to the power supply line 12V_PROT all the time. The controller <NUM> also needs to sample the output of the ADC <NUM> periodically to determine whether the battery voltage is undergoing any changes, such as the battery voltage variations that take place during cranking. This requires the controller <NUM> to wake up periodically from sleep (or low-power) mode. The ADC <NUM> also needs to be kickstarted periodically to convert the analog voltage of the voltage monitor output <NUM> into a digital value <NUM>. Waking up the controller <NUM> and causing the ADC <NUM> to perform a conversion operation both consume battery power. Additionally, the voltage monitor <NUM> draws current at all times. For the embodiment of <FIG>, the voltage monitor <NUM> draws <NUM> mA all the time assuming a 12V power supply line 12V_PROT and with the depicted resistance values. With reference back to <FIG>, the voltage monitor <NUM> draws that current even during sleep durations as current still flows through the voltage monitor <NUM> even when the controller <NUM> is in sleep mode. Consequently, the sleep power consumption level <NUM> of the telematics device is increased. In other words, the telematics device <NUM> draws electric current from the battery while the telematics device <NUM> is in a sleep duration as a result of having a voltage monitor <NUM> that is constantly drawing current from the battery <NUM>.

The inventor has realized that it is wasteful to have the voltage monitor <NUM> draw current at all times, particularly when a vehicle is parked for days or even weeks and the ignition is not turned on for a long time. The same applies to any machine having an engine that is not turned on and thus not undergoing any cranking. The voltage monitor <NUM> is unnecessarily contributing to draining the battery. Additionally, a frequent wake-up cycle for the controller <NUM>, which is necessary to capture many voltage values during cranking, also drains the battery due to both the controller <NUM> and the ADC <NUM> consuming power, even when the battery voltage is not changing. The inventor has come up with a telematics device <NUM> having a switchable voltage monitor that is switched on at the outset of cranking an engine. The inventor has also come up with a voltage drop detector that detects the onset of the cranking event by detecting the voltage drop in the battery voltage that is typical of a cranking event. As a result, the cranking voltage is determined when cranking takes place but the switchable voltage monitor is otherwise drawing zero current (and thus having zero power) when switched off. The switchable voltage monitor is switched off when there are no significant changes to the battery voltage typical of cranking. Additionally, the controller <NUM> and the ADC <NUM> do not draw current until a cranking event has been detected, as will be described in more detail below.

With reference to <FIG>, there is shown a telematics device <NUM> having the capability to detect cranking events and to enable a switchable voltage monitor <NUM> in response to a cranking event, in accordance with embodiments of the present disclosure. The telematics device <NUM> has a controller <NUM>, a memory <NUM>, a network interface <NUM>, a load dump <NUM>, a voltage drop detector <NUM>, an ADC <NUM>, and a switchable voltage monitor <NUM>.

The controller <NUM>, the memory <NUM>, the network interface <NUM>, the load dump <NUM>, and the ADC <NUM> have all been described above with reference to <FIG>.

The voltage drop detector <NUM> is an electronic module that detects a voltage drop in the battery voltage that is greater than a voltage drop threshold that is characteristic of cranking. The voltage drop detector <NUM> is connected to the power supply line 12V_PROT. When the battery voltage drops, the voltage drop is detectable on the power supply line 12V_PROT.

Upon detecting the voltage drop in the vehicle battery voltage, the voltage drop detector <NUM> triggers a cranking event with the controller <NUM>. For example, the voltage drop detector may wake up the controller <NUM> using a signal indicative of the cranking event. In some embodiments, the voltage drop detector asserts a pin or a wake-up signal line that generates an interrupt at the controller <NUM>. In the depicted embodiment, when the voltage on the power supply line 12V_PROT drops by a voltage drop threshold that is characteristic of cranking, the voltage drop detector asserts the cranking event signal <NUM>. The controller <NUM> may be configured to wake up from sleep in response to cranking event signal <NUM> being asserted. When the controller <NUM> wakes up from sleep, the controller <NUM> determines, based on the pin or signal that caused the wake-up the cause for waking up from sleep is that the battery voltage has dropped by a voltage drop that is greater than a voltage drop threshold indicative of cranking. In some embodiments, the cranking event triggers an interrupt. The controller <NUM> may have multiple pins that are configured as interrupt pins and cause the controller <NUM> to wake up. As is known in the art, the controller <NUM> can distinguish the pin that caused the interrupt event to occur. In the depicted embodiment, the controller <NUM> associates a wakeup event or a wakeup interrupt as a result of the cranking event signal <NUM> being asserted with a cranking event.

The switchable voltage monitor <NUM> is a switchable electronic module that monitors the voltage of the battery. For example, the switchable voltage monitor <NUM> is connected with the protected output of the load dump <NUM> (i.e., the protected power supply line 12V_PROT) and provides an analog voltage to the ADC <NUM>. What differentiates the switchable voltage monitor <NUM> from the voltage monitor <NUM> is that the switchable voltage monitor <NUM> is switched off until it receives an enable signal on the voltage monitor enablement signal <NUM>. Consequently, the switchable voltage monitor <NUM> is mostly off. When the switchable voltage monitor <NUM> is off, the switchable voltage monitor <NUM> draws little to no electric current and thus consumes little to zero power. When the switchable voltage monitor <NUM> is switched on, the switchable voltage monitor <NUM> is connected with the battery and provides an output voltage indicative of the battery voltage on the voltage monitor output <NUM>.

In operation, the voltage drop detector <NUM> monitors the vehicle battery voltage. In the depicted embodiment, the voltage drop detector <NUM> monitors the voltage on the 12V_PROT line. When the voltage drop detector <NUM> detects a drop in the vehicle battery voltage that is above a particular voltage drop threshold, then the voltage drop detector triggers a cranking event to the controller <NUM>. In the depicted embodiment, the voltage drop detector <NUM> asserts the cranking event signal <NUM> which triggers a cranking event at the controller <NUM>.

In some embodiments, the cranking event signal <NUM> is connected to an interrupt pin on the controller <NUM>. When the cranking event signal <NUM> is triggered, the controller <NUM> detects an interrupt event. If the controller <NUM> was in sleep mode, the controller <NUM> wakes up from sleep mode because of the interrupt event being triggered. The controller <NUM> determines that the cause of the interrupt is a cranking event based on the identity of the pin connected to the cranking event signal <NUM>. In response to determining that a cranking event has taken place, the telematics device <NUM> switches on the switchable voltage monitor <NUM>. For example, the switchable voltage monitor <NUM> may have an enable signal line connected to the controller <NUM> thus enabling the controller <NUM> to switch on and switch off the switchable voltage monitor <NUM>. In the depicted embodiment, the controller <NUM> switches on the switchable voltage monitor <NUM> by asserting the voltage monitor enablement signal <NUM>. Asserting the voltage monitor enablement signal <NUM> switches on the switchable voltage monitor <NUM>. When the switchable voltage monitor <NUM> is switched on, the switchable voltage monitor reads the battery voltage off of the 12V_PROT line and provides a voltage monitor output <NUM> indicative of the battery voltage.

In the depicted embodiment, the controller <NUM> also handles the cranking event by asserting a start conversion signal <NUM> that causes the ADC <NUM> to start converting the voltage at the voltage monitor output <NUM> to a digital value <NUM>. As shown, the voltage monitor output <NUM> of the switchable voltage monitor <NUM> is connected to the ADC <NUM>. The ADC <NUM> may be configured to be in idle mode until a start conversion signal thereof is asserted. In the depicted embodiment, in response to detecting a cranking event, the controller <NUM> asserts the start conversion signal <NUM> which causes the ADC to begin a conversion cycle of the analog voltage on the voltage monitor output <NUM> into a digital value that can be read by the controller <NUM>.

In some embodiments, the controller <NUM> periodically starts a conversion cycle on the ADC <NUM> to capture different voltage values during cranking. For example, in response to detecting a cranking event, the controller <NUM> may start a periodic timer. In response to the expiry of each period of the periodic timer, the controller <NUM> starts a conversion cycle at the ADC <NUM> by asserting the start conversion signal <NUM>.

In other embodiments, the controller <NUM> keeps the start conversion signal <NUM> asserted from the point of detecting a cranking event until the telematics device <NUM> detects an ignition off event. In this case, it is assumed that the ADC <NUM> will begin a new conversion of the analog voltage on the voltage monitor output <NUM> as soon as a previous conversion cycle has concluded.

In some embodiments, in response to detecting the cranking event, the controller <NUM> periodically asserts the voltage monitor enablement signal <NUM> to enable the switchable voltage monitor <NUM> to output an analog voltage at the voltage monitor output <NUM>. The controller <NUM> then asserts the start conversion signal <NUM> to convert the analog voltage at the voltage monitor output <NUM> to a digital value <NUM>. Subsequent to reading the digital value <NUM> off of the ADC <NUM>, the controller <NUM> de-asserts the voltage monitor enablement signal <NUM> for a period of time to save power. In other words, the controller <NUM> periodically asserts and de-asserts the voltage monitor enablement signal <NUM> in order to capture discrete values of the battery voltage which may represent cranking voltage values or device voltage values.

In some embodiments, when the telematics device <NUM> detects that the engine of the asset <NUM> (i.e., the machine or vehicle) to which the telematics device <NUM> is coupled has been turned on and is running, then the telematics device <NUM> may keep the voltage monitor enablement signal <NUM> asserted. As the engine is running, the alternator is generating electric power, and the switchable voltage monitor <NUM> will not drain the battery even if kept on at all times. In other embodiments, the controller <NUM> periodically switches on and switches off the switchable voltage monitor <NUM> to obtain voltage values representing the battery voltage, as described above. Detecting that the engine is running may be determined by determining that the revolutions-per-minute (RPM) of the engine are greater than zero. The RPM is one of the vehicle parameters that may be requested by the telematics device <NUM> from the ECUs <NUM> of the engine via the interface port.

In some embodiments, when the engine of the machine or vehicle to which the telematics device <NUM> is connected is turned off, the telematics device <NUM> switches off the switchable voltage monitor <NUM> until a subsequent cranking event is detected. For example, when the engine is turned off, the controller <NUM> de-asserts the <NUM> line thus switching off the switchable voltage monitor. Additionally, the controller <NUM> also refrains from periodically starting a conversion cycle with the ADC <NUM>, in response to detecting that the engine has been turned off. Detecting that the engine has been turned off may comprise determining that the RPM thereof is zero.

Advantageously, the switchable voltage monitor is only enabled when the vehicle is on, the engine is running, and the alternator is charging the battery. Accordingly, the vehicle battery is not drained by any current drawn by the switchable battery monitor. Additionally, the need to periodically wake up the controller <NUM> and enable the ADC <NUM>, even when no changes are taking place to the battery volage (as there is no cranking) is averted further reducing the power consumption resulting from waking up the controller <NUM> and from the ADC performing a conversion cycle.

An exemplary implementation of the voltage drop detector used to detect cranking is provided with reference to <FIG>. However, it would be apparent to persons skilled in the art that some variations of the exemplary implementation are also possible.

<FIG> is a schematic depicting an implementation of the voltage drop detector <NUM>, in accordance with embodiments of the present disclosure. The depicted implementation of the voltage drop detector <NUM> utilizes a PNP transistor Q<NUM> connected at the emitter (<NUM>) side thereof to a <NUM>. A <NUM> resistor R<NUM> connects the collector (<NUM>) of Q<NUM> to the ground (GND). The output signal of the voltage drop detector <NUM> is the cranking event signal <NUM> discussed above and is taken between the collector (<NUM>) of Q<NUM> and the resistor R<NUM>. Both the emitter (<NUM>) and the base (<NUM>) are connected to the same point each via a <NUM> resistor, namely the resistors R<NUM> and R<NUM>. The emitter (<NUM>) and the base (<NUM>) are connected to one plate of a capacitor C<NUM>. The opposite plate of the capacitor C<NUM> is connected to the power supply line 12V_PROT discussed above.

At steady state, the power supply line 12V_PROT is at 12V and the voltage at the emitter (<NUM>) of Q<NUM> is at <NUM>. No current is flowing through R<NUM>. Accordingly, the voltage at the base (<NUM>) of Q<NUM> is also at <NUM>. Accordingly, the voltage VEB for Q<NUM> is a negative value and lower than the turn on voltage of the emitter base junction of Q<NUM> (which is <NUM>. 7V), then Q<NUM> is off. Since the transistor Q<NUM> is off, the cranking event signal <NUM> is low as it is connected to the ground via R<NUM> and no current is flowing through R<NUM> (since Q<NUM> is off) and accordingly, there is no voltage drop across R<NUM>.

As the vehicle's engine is cranked, the voltage at the power supply line 12V_PROT drops (see <FIG>), by as much as 1V-3V, or approximately 2V down to 10V, which is the minimum cranking voltage <NUM>. As the voltage on the power supply line 12V_PROT drops, the voltage at point (<NUM>) also drops, and in turn the voltage at the base (<NUM>) of Q<NUM> drops. As 12V_PROT keeps dropping, so does the voltage at the base (<NUM>) of Q<NUM>. At some point, the voltage between the emitter (<NUM>) and the base (<NUM>) of Q<NUM> exceeds the turn on voltage (<NUM>. 7V) at VEB of Q<NUM>. In this case, the <NUM>. 7V represents a voltage threshold at and beyond which drops in the voltage on the power supply line 12V_PROT turn on the transistor Q<NUM>. The transistor Q<NUM> turns on and current flows through Q<NUM> causing a voltage drop across R<NUM>. Hence, the cranking event signal <NUM> is asserted (becomes high), which triggers a wake up event at the controller <NUM> as discussed above.

A simulation of the implementation of <FIG> of the voltage drop detector <NUM> on the Spice™ analog electronic circuit simulator is shown in <FIG>. In <FIG>, the signal V(n002) represents the voltage V1 which is equivalent to the power supply line 12V_PROT. The signal V(n002) simulates the voltage drop in the 12V_PROT during cranking. As shown the signal V(n002) is dropped from 12V down to 10V over a <NUM> duration, kept at 10V for a <NUM> duration, and then ramped back up to 12V over a <NUM> duration. The signal V(n003) represents the voltage at the base of Q<NUM>. As the voltage at the base drops below <NUM>. 6V, the voltage difference between the emitter and the base of Q<NUM> exceeds <NUM>. 7V and Q<NUM> turns on. The cranking event signal <NUM> is shown as V(n005). As shown V(n005) is asserted as soon as Q<NUM> turns on.

Advantageously, the voltage drop detector <NUM> only draws power from the battery once cranking has commenced. The switchable voltage monitor <NUM> is enabled by the controller <NUM> in response to a cranking event being triggered, i.e., when the cranking event signal <NUM> is asserted. Since the cranking voltage may drop by 2V or even as much as <NUM>. 5V, only a small portion of the cranking (i.e., the initial <NUM>. 7V drop) takes place while the switchable voltage monitor <NUM> is off. In other words, the onset of the cranking voltage drop is not captured until the battery voltage has dropped by <NUM>. 7V or more during cranking. This, however, is a minor portion of the cranking voltage profile.

An exemplary implementation of the switchable voltage monitor is described below with reference to <FIG>. However, it would be apparent to those of skill in the art that variations in the implementation are possible.

Referring back to <FIG>, it is noted that after the minimum cranking voltage <NUM>, the battery voltage rises at the power supply line 12V_PROT. Accordingly, the voltage at the base (<NUM>) of the transistor Q12 also rises until the voltage across VEB is less than the voltage threshold that caused Q12 to turn on (i.e., <NUM>. 7V or the turn-on voltage of the emitter-base junction of Q12). Accordingly, as cranking is concluded the voltage drop detector <NUM> is off and not consuming any power.

<FIG> depicts an implementation of a switchable voltage monitor <NUM>, in accordance with an embodiment of the present disclosure. The switchable voltage monitor <NUM> is comprised of an input-controlled switching module <NUM> in the form of a resistor-equipped double transistors module and a voltage monitor <NUM> in the form of the resistor divider circuit of <FIG>. The resistor-equipped double transistors module is an integrated module that is commercially available. For example, the NHUMD3/<NUM>/<NUM> series from Nexperia™ is a resistor-equipped double transistors module.

The input signal to the switchable voltage monitor <NUM> is a voltage monitor enablement signal <NUM> which is output from the controller <NUM>, for example via a general-purpose input/output (GPIO) pin.

The resistor-equipped double transistors module has the depicted structure. The transistor Q1 is an NPN transistor and the transistor Q2 is a PNP transistor.

As discussed above, with the ignition off in the vehicle, the controller <NUM> keeps the voltage monitor enablement signal <NUM> de-asserted until the controller <NUM> determines that a cranking event has taken place. When the voltage monitor enablement signal <NUM> is de-asserted (i.e., low), the base and emitter of the transistor Q2 are at a logic low since they are both connected to the ground. Accordingly, the transistor Q<NUM> is off because the base-emitter voltage (VBE) thereof is <NUM>, which is less than <NUM>. No current flows through R<NUM> or R<NUM>.

When the voltage monitor enablement signal <NUM> is asserted, by the controller <NUM>, the voltage of the voltage monitor enablement signal <NUM> is at logic high (e.g. 5V or <NUM>. This causes current to flows through R<NUM> and R<NUM>. If the voltage monitor enablement signal <NUM> is <NUM>. 3V, there is a voltage drop of <NUM>. 65V across R<NUM> (since R<NUM> and R<NUM> are equal). Alternatively, if the voltage monitor enablement signal <NUM> is 5V, the voltage drop across R<NUM> would be <NUM>. Since the voltage across R<NUM> is also the voltage between the base and emitter of Q<NUM>, then Q<NUM> turns on as VBE thereof is greater than <NUM>. 7V (the junction turn-on voltage of the base-emitter P-N junction). When Q<NUM> turns on, current flows through R<NUM> and R<NUM>. Since the power supply line 12V_PROT is at 12V, there is a voltage drop of approximately 6V across R<NUM>. Accordingly, VEB for Q<NUM> is around 6V. Since Q<NUM> is a PNP transistor, Q<NUM> turns on when VEB thereof is greater than <NUM>. Consequently, Q<NUM> turns on and current flows through R<NUM> and R<NUM>. The voltage monitor output <NUM> is taken between R<NUM> and R<NUM> as described above. The voltage monitor output <NUM> is provided to an ADC such as the ADC <NUM> and converted to a digital value representative of the battery voltage during cranking and subsequent to the cranking as long as the voltage monitor enablement signal <NUM> is asserted.

The switchable voltage monitor <NUM> is comprised of an input-controlled switching module <NUM> and a voltage monitor <NUM>. The input-controlled switching module <NUM> enables the voltage monitor <NUM> to provide a voltage monitor output <NUM> when the voltage monitor enablement signal <NUM> to the input-controlled switching module <NUM> is asserted. Advantageously, the switchable voltage monitor <NUM> draws very little to no current when the voltage monitor enablement signal <NUM> of the input-controlled switching module <NUM> is de-asserted since the NPN transistor Q<NUM> is off thus isolating the voltage monitor <NUM> from the power supply line 12V_PROT.

The combination of the voltage drop detector <NUM> and the switchable voltage monitor <NUM> ensure accurate capture of the cranking voltage with little to no power consumption. The voltage drop detector <NUM> avoids the need for the controller <NUM> to periodically wake up and enable the ADC <NUM> to read the battery voltage, when the ignition of the vehicle is off, in order to capture potential cranking voltage values. Keeping the controller <NUM> in sleep mode for longer periods and keeping the ADC <NUM> in low-power mode both reduce the power consumption of the telematics device <NUM> and reduce the possibility of draining the vehicle battery. Additionally, the voltage drop detector <NUM> allows the use of a switchable voltage monitor <NUM> that is enabled via an input signal, such as the voltage monitor enablement signal <NUM>. Since the voltage drop detector <NUM> can provide a cranking event signal to the controller <NUM>, the controller <NUM> can enable the switchable voltage monitor <NUM> to capture cranking voltages in response to detecting the cranking event. Advantageously, the switchable voltage monitor <NUM> only consumes power when detecting a voltage during cranking and thereafter when ignition is on. When ignition is off, the switchable voltage monitor <NUM> consumes little to no current unless a cranking event is detected. Thus a telematics device <NUM> coupled to a vehicle and employing the voltage drop detector <NUM> and a switchable voltage monitor <NUM> as described is capable of providing accurate detection of a cranking event and accurate capture of cranking voltages, without draining the vehicle battery.

<FIG> depicts a method <NUM> by a telematics device, in accordance with embodiments of the present disclosure. The telematics device <NUM> is coupled to a machine, such as a vehicle, having an engine coupled to a starter motor powered by a battery of the machine.

At step <NUM>, a voltage drop detector connected with the battery detects a voltage drop in the battery voltage, the voltage drop being greater than a voltage drop threshold.

At step <NUM>, in response to detecting the voltage drop, the voltage drop detector triggers a cranking event on a controller of the telematics device.

At step <NUM>, in response to the cranking event, the controller switches on a switchable voltage monitor connected with the battery.

While the telematics device <NUM> has been given in the context of use in vehicles, this is not necessarily the case. For example, the telematics device <NUM> may be used to capture the cranking voltage in any machine having an engine that is started by a battery-powered starter motor.

Claim 1:
A method to be performed by a telematics device (<NUM>, <NUM>) coupled to a machine (<NUM>), the machine (<NUM>) having an engine (<NUM>) coupled to a starter motor (<NUM>) powered by a battery (<NUM>) of the machine (<NUM>), the method comprising:
detecting, by a voltage drop detector (<NUM>) connected with the battery (<NUM>), a voltage drop in a battery voltage of the battery (<NUM>) that is greater than a voltage drop threshold;
in response to detecting the voltage drop:
triggering, by the voltage drop detector (<NUM>), a cranking event on a controller (<NUM>) of the telematics device (<NUM>, <NUM>); and
in response to the cranking event:
switching on, by the controller (<NUM>), a switchable voltage monitor (<NUM>) connected with the battery (<NUM>),
characterized in that
the voltage drop detector (<NUM>) is configured to consume essentially no power except when the voltage drop in the battery voltage is greater than the voltage drop threshold.