Patent Description:
A vehicle can be equipped with multiple sensors such as radar sensors, LIDAR sensors and image sensors, sensing the environment of the vehicle, and multiple safety related devices. All these components need to communicate with each other. Generally, the vehicle comprises an internal communications network like a CAN (Controller Area Network) bus that interconnects the components, typically with cable connections.

In a long vehicle and/or in a vehicle comprising two detachable parts like a truck having a tractor and a trailer, the use of cables to connect a sensor mounted on the trailer to the internal communications network located within the tractor is complicated and may not be reliable. Indeed, in such case, only a limited number of wires can be distributed between tractor and the trailer and the risk of cabling failure is important.

A known solution consists in providing a wireless communication means between the sensor mounted on the trailer and the internal communications network of the tractor. There exist wireless trailer mounted cameras. However, these cameras do not provide very reliable transmissions, for example when the radio <NUM>,<NUM> or <NUM> bands (also used in Wi-Fi communications) are used, due to interferences with other systems. Another issue is the large delays that appear when the Wi-Fi communication is used, that may cause a delay in video stream. <CIT> discloses a radar system including two adjacent radar sensor modules having directional antennas which orientation can be controlled. Each radar sensor module produces a narrow main lobe than can have different angular positions so that it can monitor a desired detection range A, B. In a configuration, the main lobes of the two radar sensor modules both extend into an overlapping area C of the two detection ranges A, B. In such circumstances, one of the two radar sensor modules receives a transmit signal, emitted by the adjacent sensor module to the overlapping area C, via the main lobe produced by this adjacent sensor module.

<CIT> shows a system providing two pairs of object detection sensors, respectively disposed on the left and right sides of the vehicle with respect to a forward direction of travel, in order to optimize the coverage of the system. <CIT> discloses a vehicle including a combined radar and wireless communication system that is configured, in a motion mode, to use the radar waveform for communication with other vehicles. The system of this document includes a waveform generator for synthesizing a combined radar and information waveform.

There is a need to improve the situation. In particular, there is a need to reduce the cabling for example between the tractor and the trailer of a vehicle like a truck equipped with detection object sensors.

The present disclosure concerns an object detection system according to claim <NUM>.

The "original" signal refers to the signal that is initially emitted (radiated at various angles) by the transmitter sensor of object detection. The "reflected" or "returned" signal refers to the signal that is reflected off the object.

The present disclosure originates from a problem of establishing a communication between a sensor of object detection, mounted on the trailer of a vehicle like a truck, and the main vehicle's network located within a tractor part of the vehicle, but applies to many other configurations of an object detection system including at least two sensors of object detection.

According to the present disclosure, the signal radiated at various angles by one of the two sensors is modulated to include the data to be transmitted to the other sensor. The other sensor can receive side lobes of the original signal modulated radiated by the transmitting antenna of the transmitter sensor and decode the received signal by demodulation to obtain said data. The original signal radiated by the transmitter sensor is used as a carrier signal to transmit data to the receiver sensor. This carrier signal is modulated by the data to be transmitted.

The transmitting antenna, typically a directional antenna, is designed to radiate most of its power in one lobe, called the main lobe, directed in a desired direction. The other lobes, called "side lobes", generally represent unwanted radiation in other directions. In the technical field of antenna, side lobes or "sidelobes" are the lobes (local maxima) of the far field radiation pattern of the antenna (or other radiation source), that are not the main lobe. The present disclosure uses these side lobes to transmit data from one sensor to the other sensor. This allows to provide a side communication channel between the two sensors of object detection. This side communication channel can be used to transfer data like sensor data, or any other type of data. Furthermore, such a communication between the two sensors can be achieved by energy harvesting, using part of the power radiated by the transmitter sensor.

Advantageously, the two sensors are disposed so that the receiving antenna of the receiver sensor can receive the side lobes radiated by the transmitting antenna of the transmitter sensor within an angular range. In other words, the relative positions of the two sensors are such that one sensor can receive the side lobes radiated by the other sensor within an angular range.

The transmitter of the transmitter sensor can modulate the original signal by varying at least one property of the group including a frequency, a phase and an amplitude of the original signal. For example, the transmitter of the transmitter sensor can encode the data by frequency modulation, typically by modulating the transmission frequency of the signal radiated (i.e., emitted according to a radiation pattern having a main lobe and side lobes) by the transmitter sensor.

In a first embodiment, the transmitter sensor transmits the original signal modulated between two successive operations of object detection performed by the transmitter sensor. Thus, the transmitter sensor transmits data to the receiver sensor when object detection is not performed. In this embodiment, the transmitter sensor can perform object detection, such as a range measurement, by emitting a signal having a normal transmission frequency (not modified). The transmitter sensor can alternatively perform object detection (e.g. range measurement) and transmission of data to the receiver sensor, for example at predetermined successive periods of time.

Advantageously, the receiver sensor concomitantly receives the original signal modulated between two successive operations of object detection. The transmitter sensor and the receiver sensor are advantageously synchronized to transmit and receive data at the same time.

In a second embodiment, the transmitter sensor modulates the original signal and radiates the original signal modulated, while using said original signal modulated to concomitantly perform object detection. In this embodiment, the transmitter sensor concomitantly performs object detection and transmission of data by radiating a modulated signal.

The two sensors of object detection can be radar sensors.

The object detection system can further comprise a controller that controls the sensors of object detection. Only one of the two sensors of object detection can be connected to the controller with a connection link, such as a cable, and the two sensors can be arranged so that communication between the non-connected sensor and the controller is achieved through a communication between the two sensors.

The object detection system can further comprise one or more other components connected to the non-connected sensor with a connection link, that can communicate with the controller by using the communication between the two sensors of object detection. The other component(s) can include other sensor(s).

The present disclosure also concerns a sensor of objection detection, suitable to be used in the system defined above, comprising a transmitter for producing an original periodic signal, one or two antennas for transmitting the original signal and, after the original signal has reflected off the object, receiving a reflected signal, and a receiver for detecting an information related to the object using the received reflected signal, wherein the transmitting antenna has a radiation pattern including a main lobe and side lobes at various angles, characterized in that
the transmitter encodes data to be transmitted to another object detection sensor by modulating the original signal radiated by the transmitting antenna.

The receiving antenna can be arranged to receive a signal and the receiver can be arranged to decode the received signal by demodulation to obtain data encoded within the received signal.

The present disclosure further concerns a vehicle comprising the object detection system as previously defined.

The vehicle can comprise a tractor and a trailer. The tractor can comprise one of the two sensors and the trailer can comprise the other sensor. The sensor of the tractor can be a connected sensor, and the sensor of the trailer can be a non-connected sensor.

Optionally, the vehicle comprises two pairs of object detection sensors, respectively disposed on the left and right sides of the vehicle with respect to the forward direction of travel of the vehicle. In this particular implementation, the two pairs of sensors are used in parallel (one on each side of the vehicle). Such a configuration provides an unbreakable communication, even when the vehicle turns left or right and causes that the respective coverage areas of the two coupled sensors do not overlap temporarily.

The present disclosure also concerns a method of communication between two sensors of object detection, wherein.

The receiver sensor can receive the original signal modulated by receiving side lobes radiated by the transmitting antenna of the transmitter sensor and decodes the received signal by demodulation to obtain said data.

In case that only one of the two sensors is connected to a controller with a connection link, a communication between the non-connected sensor and the controller can be achieved through a communication between the two sensors.

A vehicle has a plurality of automotive electronic systems, that are distributed systems, classified for example as engine electronics, transmission electronics, chassis electronics, passive safety, driver assistance, passenger comfort, entertainment systems, electronic integrated cockpit systems. Sensors are components of these automotive electronic systems.

For use in these automotive electronic systems, there are many types of sensors. There are in particular sensors of object detection that can be used for range measurement to the object, detection of an obstacle, detection of a property of the object like its speed, acceleration, or others, etc.. Typically, in a vehicle, the sensors of object detection can be cameras, radar sensors or LIDAR sensors. The vehicle can have a plurality of sensors of object detection that need to communicate with a controller (or possibly several controllers), such as an electronic control unit (ECU), having the function of controlling the sensors. The sensors may be located near the ECU or remote from the ECU. In the first case, the sensors can be easily connected to the ECU using a link connection like a cable, typically through an internal communications network like a CAN (Controller Area Network) bus. In the second case, it might be difficult or not convenient to connect the remote sensor(s) to the ECU using a connection link like a cable. The present disclosure allows to establish a communication between the controller and the one or more remote sensors without connection link a cable.

The present disclosure concerns more particularly an object detection system <NUM>, suitable to be used within a vehicle (for example the vehicle <NUM> in <FIG>), having at least two sensors of object detection <NUM>, <NUM> that each have :.

wherein the transmitting antenna <NUM>, <NUM> has a radiation pattern including a main lobe <NUM> and side lobes <NUM> at various angles, as represented in <FIG>.

In the present disclosure, the terms "transmitting antenna" mean a radiation source designed to radiates waves such as electromagnetic waves. The terms "receiving antenna" mean a radiation receptor designed to receive these waves. A transmitting and receiving antenna is a device that is both a radiation source and a radiation receptor.

In each sensor <NUM>, <NUM>, the transmitting antenna <NUM>, <NUM> is a directional antenna that is configured to emit a signal of electromagnetic waves in one particular direction. More precisely, the antenna <NUM>, <NUM> is designed to radiate most of its power in one lobe directed in a desired direction. This lobe is called the "main lobe" <NUM>. The other lobes, called "side lobes" <NUM>, represent unwanted radiation in other directions. The side lobes can include a back lobe (not represented in <FIG>) that is a side lobe directly behind the main lobe. In the radiation pattern, the main lobe <NUM> is larger than the side lobes <NUM>. The axis of maximum radiation passes through the center of the main lobe <NUM>.

In the illustrative example of <FIG>, the antenna <NUM> (or <NUM>) corresponds to the center of the polar radiation plot represented and the axis of maximum radiation has an angle around <NUM>,<NUM>° with respect the direction <NUM>°. The main lobe <NUM> occupies an angular range between <NUM>° and <NUM>° and the sides lobes extend over a first angular range from <NUM>° to <NUM>° and a second angular range from <NUM>° to <NUM>°. Other configurations are possible. The example of <FIG> is only a illustrative and non limitative example.

The two sensors <NUM>, <NUM> are for example radar sensors. But other types of sensors (LIDAR, ultra-sound, etc.) could be used.

The two sensors <NUM>, <NUM> have respective coverage areas that overlap to allow communication between the two sensors. In other words, the coverage area of the transmitter sensor <NUM> covers part of the coverage area of the receiver sensor <NUM>. The two sensors <NUM>, <NUM> are disposed so that the receiving antenna <NUM> of the receiver sensor <NUM> can receive at least the side lobes radiated by the transmitting antenna <NUM> of the transmitter sensor <NUM> within an angular range Ω. To achieve a bidirectional communication between them, the two sensors <NUM>, <NUM> are disposed so that each sensor can receive at least the side lobes radiated by the other sensor within a respective angular range Ω<NUM>, Ω<NUM>.

A side communication channel between the two sensors of object detection <NUM>, <NUM> can be established to transmit data from one sensor to the other sensor, using some lobes of the radiation pattern of the transmitting antenna, typically side lobes. For the purpose of illustration, let's assume that the sensor <NUM> is the transmitter sensor and the sensor <NUM> is the receiver sensor. A transmission of data in the other direction, from the sensor <NUM> to the sensor <NUM>, could be done in the same way.

The transmitter <NUM> of the transmitter sensor <NUM> produces an original periodic signal having a transmission frequency and encodes the data to be transmitted by modulating this original signal <NUM>. The signal can be modulated by frequency modulation, as explained below.

The transmitter sensor <NUM> is normally used to perform object detection. In a use case of objection detection, the original signal produced by the transmitter <NUM> has a given transmission frequency. In the present disclosure, the transmitter sensor <NUM> can be used to transmit data to the receiver sensor <NUM>. In that case, the transmitter <NUM> modulates the original signal by modulating its transmission frequency depending on the data to be transmitted. In other words, the transmission frequency of the original signal produced and radiated by the transmitter sensor <NUM> is modulated depending on the data to be transmitted, so that the radiated original signal includes the encoded data. The transmitting antenna <NUM> of the transmitter sensor <NUM> then emits the modulated original signal with a radiation pattern <NUM> that includes a main lobe <NUM> and side lobes <NUM> at various angles, as shown in <FIG>. The signal <NUM> radiated in various angles includes the encoded data (modulating the transmission frequency of the radiated signal).

Depending on the relative positions of the two sensors of object detection <NUM> and <NUM> (i.e., depending on how the respective coverage areas of the two sensors <NUM>, <NUM> overlap), the receiving antenna <NUM> of the receiver sensor <NUM> receives at least a part of the side lobes <NUM> of the signal <NUM> (modulated) radiated by the transmitting antenna <NUM>. According to the invention, the receiving antenna <NUM> can receive only the side lobes <NUM> of the signal radiated by the antenna <NUM> at angles within an angular range Ω<NUM>, for example between <NUM>° and <NUM>°, or more precisely between <NUM>° and <NUM>° (as represented in <FIG>). Then, the receiver <NUM> of the receiver sensor <NUM> processes the received signal including the received side lobes of the signal to determine the transmitted data by demodulation.

In a first embodiment, the transmitter sensor <NUM> transmits the original signal modulated, including the encoded data, between two successive operations of object detection performed by the transmitter sensor <NUM>. The receiver sensor <NUM> concomitantly receives the original signal modulated, including the encoded data, between two successives operations of object detection. In other words, the transmitter sensor <NUM> and the receiver sensor <NUM> respectively transmit and receive the signal at the same time between successive operations of object detection. For example, the transmitter sensor <NUM> and the receiver sensor <NUM> can perform object detection and transmission/reception of data alternatively during predetermined successive periods of time, and be synchronized to perform concomitantly transmission and reception of the data, during the same predetermined periods of time.

A second embodiment of the object detection system <NUM> is based on the first embodiment and only differs from it by the features described below.

In the second embodiment, the transmitter sensor <NUM> is configured to concomitantly performs object detection and transmission of data to the receiver sensor <NUM>. The receiver sensor <NUM> is also configured to concomitantly perform object detection and reception of data from the transmitter sensor <NUM>.

In that case, the transmitter sensor <NUM> modulates the original signal and radiates the original signal modulated (including the encoded data to be transmitted), while using this original signal modulated to concomitantly perform object detection. In operation, the transmitter <NUM> produces a signal <NUM> for object detection and modulates this signal <NUM> to include the data to be transmitted. More precisely, the transmitter <NUM> modulates the transmission frequency of the original signal and the antenna <NUM> radiates the original signal modulated, including the encoded data, at various angles.

The original signal modulated is reflected by an object and the returned signal (from the original signal modulated) is received and processed by the receiver <NUM> of the sensor <NUM> to detect an information related to the object. In the processing, the receiver <NUM> takes into account the modulation applied to the original signal that has been emitted.

A third embodiment of the object detection system is based on the first or second embodiment.

In the third embodiment, the object detection system further comprises a controller, such as an ECU, that controls the sensors of object detection <NUM>, <NUM>.

Only one of the two sensors of object detection, for example the sensor <NUM>, is connected to the controller <NUM> through a connection link, such as a cable. The connection link can connect the sensor to an internal communications network <NUM>, like a CAN bus, that interconnects a plurality of components including the controller <NUM> and other components 44a-44d, for example other object detection sensors (such as camera(s), LIDAR sensor(s), other radar sensor(s)) and/or other electronic or electrical devices.

The other sensor of object detection <NUM> is a non-connected sensor. For example, the connected sensor <NUM> is located near the controller <NUM> and can easily be connected to it with a cable, and the non-connected sensor <NUM> is located remote to the controller <NUM>.

The connected sensor <NUM> and the non-connected sensor <NUM> are arranged so that communication between the non-connected sensor and the internal communications network can be achieved as previously described in the first or second embodiment. That is, the communication of data between the connected sensor <NUM> and the non-connected sensor <NUM> can be achieved by modulating the signal radiated by the transmitting antenna <NUM> of the non-connected sensor <NUM> to transmit data from the non-connected sensor <NUM> to the controller <NUM>, and by modulating the signal radiated by the transmitting antenna <NUM> of the connected sensor <NUM> to transmit data from the controller <NUM> to the non-connected sensor <NUM>.

A fourth embodiment is based on the third embodiment and only differs from it by the following features.

In the fourth embodiment, the object detection system <NUM> comprises at least one other sensor connected to the non-connected sensor with a connection link. In other words, one or more other sensors, such as the sensors 46a, 46b in <FIG>, are connected to the non-connected sensor <NUM> with a connection link such as a cable. The non-connected sensor <NUM> and the other sensor(s) 46a, 46b can be interconnected by a local communications network <NUM> like a CAN bus. This local communications network <NUM> is a secondary network, while the communications network <NUM> to which the controller is connected is a main network. For example, the other sensors 46a, 46b can include camera(s), LIDAR sensor(s), or any other type of sensor (e.g., temperature sensor, etc.).

The other sensors 46a, 46b can communicate with the controller <NUM> by using the communication between the connected sensor <NUM> and the non-connected sensor <NUM>, as previously described for example in the first, second or third embodiment.

In a variant of the fourth embodiment, the object detection system comprises at least one other component connected to the non-connected sensor with a connection link. These other component(s) can include component(s) other than sensor(s). They can communicate with the controller <NUM> by using the communication between the connected sensor <NUM> and the non-connected sensor <NUM>, as previously described for example in the first, second or third embodiment.

The present disclosure also concerns a vehicle <NUM> having an object detection system <NUM> according to one of the first, second, third or fourth embodiment, or the variant of the fourth embodiment.

<FIG> shows an example of a vehicle <NUM> that is a truck comprising a tractor <NUM> and a trailer <NUM>. The tractor <NUM> comprises one of the two sensors of object detection, for example the sensor <NUM>, and the trailer <NUM> comprises the other sensor of object detection <NUM>.

In case that the vehicle <NUM> has the object detection system <NUM> according to the third embodiment, or the fourth embodiment or the variant of the fourth embodiment, the tractor <NUM> has the sensor <NUM> connected to the controller <NUM> and the trailer <NUM> has the sensor <NUM> non-connected to the controller.

The tractor <NUM> can have an embedded system that has a plurality of components <NUM>, 44a-44d, <NUM> and an internal communications network <NUM> interconnecting these components, such as a CAN bus.

The connection link between the connected sensor and the controller (or the internal communications network to which the controller is connected), could be other than a cable. For example, it could be a wireless connection link using a standardized wireless communication protocol. The same applies for the connection link between the non-connected sensor <NUM> and the secondary communications network <NUM>.

The present disclosure also concerns a method of transmitting data between the two sensors of object detection <NUM>, <NUM>, comprising a first step of encoding S1, by the transmitter <NUM> of the transmitter sensor <NUM>, the data to be transmitted to the receiver sensor <NUM>, by modulating the ('original') signal produced by the transmitter <NUM>. As previously described, the modulation can be a frequency modulation such as a modulation of the transmission frequency of the radiated signal. More precisely, the signal has pulses emitted with given frequency that is modulated depending on the data to be transmitted.

In a second step of transmission S2, the transmitter sensor <NUM> radiates the modulated signal including the encoded data with the transmitting antenna <NUM> at various angles, according to its radiation pattern (including a main lobe <NUM> and side lobes <NUM>) as previously described. The transmission can be achieved as described in the first embodiment or the second embodiment.

In a third step of reception S3, the receiver sensor <NUM> receives side lobes of the modulated signal, which are radiated by the transmitting antenna <NUM> within an angular range of radiating angles (for example between <NUM>° and <NUM>°, or between <NUM>° and <NUM>°, in <FIG>), using its receiving antenna <NUM>.

In a fourth step of decoding S4, the receiver <NUM> of the receiver sensor <NUM> decodes the received signal by demodulation and obtains the transmitted data.

In case that only one of the two sensors <NUM> is connected to the controller <NUM> with a connection link, a communication between the non-connected sensor <NUM> and the controller <NUM> is achieved through a communication between the two sensors <NUM>, <NUM>. In the same way, a communication between another component (sensor or other) connected to the non-connected sensor <NUM> (but not connected to the controller <NUM>) and the controller <NUM> is achieved through a communication between the two sensors <NUM>, <NUM>.

In a variant, the vehicle <NUM> comprises two pairs of sensors of object detection <NUM>, <NUM>, one on each side of the vehicle. More precisely, the vehicle <NUM> comprises a first pair of sensors of object detection <NUM>, <NUM> on the right side of the vehicle <NUM> and a second pair of sensors of object detection <NUM>, <NUM> on the left side of the vehicle, the left and right sides being defined with respect to a forward direction of travel of the vehicle <NUM>. The use of two pairs of sensors of object detection, each capable of establishing a side communication channel between the two sensors, allows to provide two side communication channels, one on each side of the vehicle. Such a configuration allows to avoid a loss of communication in case that the two sensors of one of the two side communications channel have coverage areas that do not overlap temporarily due to a turn maneuver of the vehicle or a turn on a road that is not straight. It may happen that the communication between two paired sensors is lost temporarily, due to some particular circumstances, but, in such a situation, the communication between the two other paired sensors is maintained.

In another variant, the vehicle <NUM> comprises N pairs of sensors of object detection capable of establishing N side communication channels, with N><NUM>.

Claim 1:
An object detection system (<NUM>) comprising at least two sensors of object detection (<NUM>, <NUM>) that each comprise a transmitter (<NUM>, <NUM>) for producing an original periodic signal (<NUM>), one or two antennas (<NUM>, <NUM>) for transmitting the original signal (<NUM>) and, after the original signal (<NUM>) has reflected off the object, receiving a reflected signal, and a receiver (<NUM>, <NUM>) for detecting an information related to the object using the received reflected signal, wherein the transmitting antenna (<NUM>, <NUM>) has a radiation pattern including a main lobe (<NUM>) and side lobes (<NUM>) at various angles,
the two sensors (<NUM>, <NUM>) have respective coverage areas that overlap,
the transmitter (<NUM>) of one of the two sensors, that is the transmitter sensor (<NUM>), is configured to encode data to be transmitted to the other one of the two sensors, that is the receiver sensor (<NUM>), by modulating the original signal radiated by the transmitting antenna (<NUM>) of the transmitter sensor (<NUM>), the original periodic signal being used as a carrier signal that is modulated by the data to be transmitted, and characterized in that
the two sensors having relative positions in which the receiving antenna (<NUM>) of the receiver sensor (<NUM>) can only receive the side lobes (<NUM>) radiated by the transmitting antenna (<NUM>) of the transmitter sensor (<NUM>), within an angular range, the receiver sensor is configured to receive the original signal modulated via side lobes radiated by the transmitting antenna (<NUM>) of the transmitter sensor (<NUM>) and to decode the received signal by demodulation to obtain said data.