Patent Publication Number: US-2022212537-A1

Title: Vehicle speed control using speed maps

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/239,014, filed Jan. 3, 2019, entitled “VEHICLE SPEED CONTROL USING SPEED MAPS,” the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to vehicles. In particular, embodiments of the present disclosure relate to controlling the speed of a vehicle. 
     DESCRIPTION OF RELATED ART 
     Modern vehicles include many convenience features to control or assist controlling the vehicle. One such feature is often referred to as “cruise control.” With this feature, the driver may select a particular speed to be maintained by the vehicle. The vehicle then maintains that speed until the driver changes the speed, or disables cruise control, for example by turning the feature off or pressing the brake pedal. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     In one embodiment of the present invention, a method for automatically controlling the speed of a vehicle comprises receiving a first user input to initiate speed control from a driver and initiating speed control; retrieving a speed map associated with the driver, wherein the speed map is generated with the use of geographic speed limits and learned driver behaviors, the speed map comprising a plurality of entries, each entry comprising a speed limit and an offset value; recording a current speed limit and a new offset value pursuant to a second user input; adding an additional entry to the speed map comprising the current speed limit and the new offset value; and automatically setting the speed of the vehicle according to the new offset value upon subsequent operation of the vehicle at the recorded current speed limit. 
     In some embodiments, the new offset value is determined according to behavior of the driver. 
     In some embodiments, the method further comprises selecting an entry from the plurality of entries associated with the current speed limit, and updating the selected entry with the current speed limit and new offset value. 
     In some embodiments, the method further comprises automatically setting the speed of the vehicle according to the selected entry&#39;s updated speed limit and updated offset value. 
     In some embodiments, modifying the speed map comprises: measuring a speed of the vehicle; and updating an entry of the plurality of entries, wherein updating the entry comprises setting the entry&#39;s offset value as the difference between the measured speed of the vehicle and the speed limit. 
     In some embodiments, the method further comprises determining an adverse condition for the road being traveled by the vehicle; and adjusting the speed of the vehicle based on the adverse condition. 
     In some embodiments, determining an offset value comprises: when the speed map does not contain an entry for the determined speed limit, interpolating using a plurality of the entries in the speed map and generating a new entry. 
     In another embodiment, a method for automatically controlling the speed of a vehicle comprises receiving a first user input to initiate speed control from a driver and initiating speed control; determining the presence of an adverse-condition; retrieving a speed map associated with the driver, wherein the speed map is generated with the use of geographic speed limits and learned driver behaviors, the speed map comprising a plurality of entries, each entry comprising a speed limit and an offset value; and updating the plurality of entries with a plurality of offset values associated with the determined adverse condition. 
     In some embodiments, the new offset value is determined according to behavior of the driver. 
     In some embodiments, modifying the speed map comprises measuring a speed of the vehicle and recording the speed of the vehicle and the speed limit in the speed map. 
     In some embodiments, determining a desired speed comprises: when the speed map does not contain an entry for the determined speed limit, interpolating using a plurality of the entries in the speed map. 
     In some embodiments, the method further comprises selecting an entry from the plurality of entries associated with the current speed limit; and updating the selected entry with the current speed limit and new offset value. 
     In some embodiments, the method further comprises automatically setting the speed of the vehicle according to the selected entry&#39;s updated speed limit and updated offset value. 
     In another embodiment, a non-transitory machine-readable storage medium encoded with instructions executable by a hardware processor of a computing component of a vehicle, the machine-readable storage medium comprising instructions to cause the hardware processor to: receive a first user input to initiate speed control from a driver and initiating speed control; retrieve a speed map associated with the driver, wherein the speed map is generated with the use of geographic speed limits and learned driver behaviors, the speed map comprising a plurality of entries, each entry comprising a speed limit and an offset value; receive a second user input to record a speed limit and recording the current speed limit; select an entry from the plurality of entries associated with the current speed limit; and automatically set the speed of the vehicle according to selected entry&#39;s speed limit and offset value. 
     In some embodiments, the new offset value is determined according to behavior of the driver. 
     In some embodiments, the behavior of the driver takes into account at least one of road type, traffic density, and time of day. 
     In some embodiments, the instructions further cause the hardware processor to identify the driver with a plurality of biometric sensors and retrieve the speed map associated with the identified driver. 
     In some embodiments, the instructions further cause the hardware processor to measure a speed of the vehicle; and record the speed limit and an offset value in the speed map, the offset value representing a difference between the speed of the vehicle and the speed limit. 
     In some embodiments, the instructions further cause the hardware processor to determine an adverse condition for the road being traveled by the vehicle and adjust the speed of the vehicle based on the adverse condition. 
     In some embodiments, the instructions further cause the hardware processor to: when the speed map does not contain an entry for the determined speed limit, interpolating using a plurality of the entries in the speed map and generating a new entry. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The figures are provided for purposes of illustration only and merely depict typical or example embodiments. 
         FIG. 1  illustrates an example vehicle in which embodiments of the disclosed technology may be implemented. 
         FIG. 2  illustrates an example architecture for controlling the speed of a vehicle in accordance with one embodiment of the systems and methods described herein. 
         FIG. 3  is a flowchart illustrating a process for controlling the speed of a vehicle using offset speeds according to one embodiment. 
         FIG. 4  shows an example speed map storing offset speeds according to one embodiment. 
         FIG. 5  is a flowchart illustrating a process for controlling the speed of a vehicle using desired speeds according to one embodiment. 
         FIG. 6  shows an example speed map storing desired speeds according to one embodiment. 
         FIG. 7  is a flowchart illustrating a process for learning a speed map according to one embodiment. 
         FIG. 8  shows a speed map using adverse conditions offsets. 
         FIG. 9  shows an example computing component according to various embodiments. 
     
    
    
     The figures are not exhaustive and do not limit the present disclosure to the precise form disclosed. 
     DETAILED DESCRIPTION 
     Various embodiments are directed to allowing a driver to set vehicle speed relative to the legal speed limit. Embodiments of the technology disclosed herein allow a driver to program a vehicle to travel at a speed set relative to the speed limit. The disclosed technology may be applied to autonomous and semi-autonomous vehicles, as well as to vehicles operated by manual driving with cruise control. 
     In some embodiments, the driver may set a universal offset to be applied to all speed limits. In other embodiments, the driver may set a different offset for different speed limits. That is, the driver may populate a speed map that contains different offsets to be applied to different determined speed limits. For instance, the driver might enter an offset of 10 mph for a speed limit of 30 mph and an offset of 5 mph for 70 mph. To set the vehicle speed, the system applies these offsets and may be configured to interpolate at speeds in between those for which an offset is defined. 
     In some embodiments, the system may learn a speed map from the driver&#39;s behaviors. For example, if the driver drives 78 when the speed limit is 70 but exactly 25 when the speed limit is 25, the system may learn this and modify the speed map accordingly. Such learning may further take into account features beyond speed limits, such as road type, traffic density, time of day, etc. 
     An example vehicle  102  in which embodiments of the disclosed technology may be implemented is illustrated in  FIG. 1 . The vehicle depicted in  FIG. 1  is a hybrid electric vehicle. However, the disclosed technology is independent of the means of propulsion of the vehicle, and so applies equally to vehicles without an electric motor, and to vehicles without an internal combustion engine. 
       FIG. 1  illustrates a drive system of a vehicle  102  that may include an internal combustion engine  110  and one or more electric motors  106  (which may also serve as generators) as sources of motive power. Driving force generated by the internal combustion engine  110  and motor  106  can be transmitted to one or more wheels  34  via a torque converter  16 , a transmission  18 , a differential gear device  28 , and a pair of axles  30 . 
     As an HEV, vehicle  102  may be driven/powered with either or both of engine  110  and the motor(s)  106  as the drive source for travel. For example, a first travel mode may be an engine-only travel mode that only uses internal combustion engine  110  as the drive source for travel. A second travel mode may be an EV travel mode that only uses the motor(s)  106  as the drive source for travel. A third travel mode may be an HEV travel mode that uses engine  110  and the motor(s)  106  as drive sources for travel. In the engine-only and HEV travel modes, vehicle  102  relies on the motive force generated at least by internal combustion engine  110 , and a clutch  15  may be included to engage engine  110 . In the EV travel mode, vehicle  102  is powered by the motive force generated by motor  106  while engine  110  may be stopped and clutch  15  disengaged. 
     Engine  110  can be an internal combustion engine such as a spark ignition (SI) engine (e.g., gasoline engine) a compression ignition (CI) engine (e.g., diesel engine) or similarly powered engine (whether reciprocating, rotary, continuous combustion or otherwise) in which fuel is injected into and combusted to provide motive power. A cooling system  112  can be provided to cool the engine such as, for example, by removing excess heat from engine  110 . For example, cooling system  112  can be implemented to include a radiator, a water pump and a series of cooling channels. In operation, the water pump circulates coolant through the engine to absorb excess heat from the engine. The heated coolant is circulated through the radiator to remove heat from the coolant, and the cold coolant can then be recirculated through the engine. A fan may also be included to increase the cooling capacity of the radiator. The water pump, and in some instances the fan, may operate via a direct or indirect coupling to the driveshaft of engine  110 . In other applications, either or both the water pump and the fan may be operated by electric current such as from battery  104 . 
     An output control circuit  14 A may be provided to control drive (output torque) of engine  110 . Output control circuit  14 A may include a throttle actuator to control an electronic throttle valve that controls fuel injection, an ignition device that controls ignition timing, and the like. Output control circuit  14 A may execute output control of engine  110  according to a command control signal(s) supplied from an electronic control unit  50 , described below. Such output control can include, for example, throttle control, fuel injection control, and ignition timing control. 
     Motor  106  can also be used to provide motive power in vehicle  102 , and is powered electrically via a battery  104 . Battery  104  may be implemented as one or more batteries or other power storage devices including, for example, lead-acid batteries, lithium ion batteries, capacitive storage devices, and so on. Battery  104  may be charged by a battery charger  108  that receives energy from internal combustion engine  110 . For example, an alternator or generator may be coupled directly or indirectly to a drive shaft of internal combustion engine  110  to generate an electrical current as a result of the operation of internal combustion engine  110 . A clutch can be included to engage/disengage the battery charger  108 . Battery  104  may also be charged by motor  106  such as, for example, by regenerative braking or by coasting during which time motor  106  operate as generator. 
     Motor  106  can be powered by battery  104  to generate a motive force to move the vehicle and adjust vehicle speed. Motor  106  can also function as a generator to generate electrical power such as, for example, when coasting or braking. Battery  104  may also be used to power other electrical or electronic systems in the vehicle. Motor  106  may be connected to battery  104  via an inverter  42 . Battery  104  can include, for example, one or more batteries, capacitive storage units, or other storage reservoirs suitable for storing electrical energy that can be used to power motor  106 . When battery  104  is implemented using one or more batteries, the batteries can include, for example, nickel metal hydride batteries, lithium ion batteries, lead acid batteries, nickel cadmium batteries, lithium ion polymer batteries, and other types of batteries. 
     An electronic control unit  50  (described below) may be included and may control the electric drive components of the vehicle as well as other vehicle components. For example, electronic control unit  50  may control inverter  42 , adjust driving current supplied to motor  106 , and adjust the current received from motor  106  during regenerative coasting and breaking. As a more particular example, output torque of the motor  106  can be increased or decreased by electronic control unit  50  through the inverter  42 . 
     A torque converter  16  can be included to control the application of power from engine  110  and motor  106  to transmission  18 . Torque converter  16  can include a viscous fluid coupling that transfers rotational power from the motive power source to the driveshaft via the transmission. Torque converter  16  can include a conventional torque converter or a lockup torque converter. In other embodiments, a mechanical clutch can be used in place of torque converter  16 . 
     Clutch  15  can be included to engage and disengage engine  110  from the drivetrain of the vehicle. In the illustrated example, a crankshaft  32 , which is an output member of engine  110 , may be selectively coupled to the motor  106  and torque converter  16  via clutch  15 . Clutch  15  can be implemented as, for example, a multiple disc type hydraulic frictional engagement device whose engagement is controlled by an actuator such as a hydraulic actuator. Clutch  15  may be controlled such that its engagement state is complete engagement, slip engagement, and complete disengagement complete disengagement, depending on the pressure applied to the clutch. For example, a torque capacity of clutch  15  may be controlled according to the hydraulic pressure supplied from a hydraulic control circuit (not illustrated). When clutch  15  is engaged, power transmission is provided in the power transmission path between the crankshaft  32  and torque converter  16 . On the other hand, when clutch  15  is disengaged, motive power from engine  110  is not delivered to the torque converter  16 . In a slip engagement state, clutch  15  is engaged, and motive power is provided to torque converter  16  according to a torque capacity (transmission torque) of the clutch  15 . 
     As alluded to above, vehicle  102  may include an electronic control unit  50 . Electronic control unit  50  may include circuitry to control various aspects of the vehicle operation. Electronic control unit  50  may include, for example, a microcomputer that includes a one or more processing units (e.g., microprocessors), memory storage (e.g., RAM, ROM, etc.), and I/O devices. The processing units of electronic control unit  50 , execute instructions stored in memory to control one or more electrical systems or subsystems in the vehicle. Electronic control unit  50  can include a plurality of electronic control units such as, for example, an electronic engine control module, a powertrain control module, a transmission control module, a suspension control module, a body control module, and so on. As a further example, electronic control units can be included to control systems and functions such as doors and door locking, lighting, human-machine interfaces, cruise control, telematics, braking systems (e.g., ABS or ESC), battery management systems, and so on. These various control units can be implemented using two or more separate electronic control units, or using a single electronic control unit. 
     In the example illustrated in  FIG. 1 , electronic control unit  50  receives information from a plurality of sensors included in vehicle  102 . For example, electronic control unit  50  may receive signals that indicate vehicle operating conditions or characteristics, or signals that can be used to derive vehicle operating conditions or characteristics. These may include, but are not limited to accelerator operation amount, A CC , a revolution speed, N E , of internal combustion engine  110  (engine RPM), a rotational speed, N MG , of the motor  106  (motor rotational speed), and vehicle speed, N V . These may also include torque converter  16  output, N T  (e.g., output amps indicative of motor output), brake operation amount/pressure, B, battery SOC (i.e., the charged amount for battery  104  detected by an SOC sensor). Accordingly, vehicle  102  can include a plurality of sensors  116  that can be used to detect various conditions internal or external to the vehicle and provide sensed conditions to engine control unit  50  (which, again, may be implemented as one or a plurality of individual control circuits). In one embodiment, sensors  116  may be included to detect one or more conditions directly or indirectly such as, for example, fuel efficiency, E F , motor efficiency, E MG , hybrid (internal combustion engine  110 +MG  12 ) efficiency, etc. 
     In some embodiments, one or more of the sensors  116  may include their own processing capability to compute the results for additional information that can be provided to electronic control unit  50 . In other embodiments, one or more sensors may be data-gathering-only sensors that provide only raw data to electronic control unit  50 . In further embodiments, hybrid sensors may be included that provide a combination of raw data and processed data to electronic control unit  50 . Sensors  116  may provide an analog output or a digital output. 
     Sensors  116  may be included to detect not only vehicle conditions but also to detect external conditions as well. Sensors that might be used to detect external conditions can include, for example, sonar, radar, lidar or other vehicle proximity sensors, and cameras or other image sensors. Image sensors can be used to detect, for example, traffic signs indicating a current speed limit, road curvature, obstacles, and so on. Still other sensors may include those that can detect road grade. While some sensors can be used to actively detect passive environmental objects, other sensors can be included and used to detect active objects such as those objects used to implement smart roadways that may actively transmit and/or receive data or other information. 
       FIG. 2  illustrates an example architecture for controlling the speed of a vehicle in accordance with one embodiment of the systems and methods described herein. Referring now to  FIG. 2 , in this example, a vehicle speed control system  200  includes a speed control circuit  250 , a plurality of sensors  116 , and a plurality of vehicle systems  158 . Sensors  116  and vehicle systems  158  can communicate with speed control circuit  250  via a wired or wireless communication interface. Although sensors  116  and vehicle systems  158  are depicted as communicating with speed control circuit  250 , they can also communicate with each other as well as with other vehicle systems. Speed control circuit  250  can be implemented as an ECU or as part of an ECU such as, for example electronic control unit  50 . In other embodiments, speed control circuit  250  can be implemented independently of the ECU. In further embodiments, speed control circuit  250  can be implemented as part of vehicle speed system  274 . 
     Speed control circuit  250  in this example includes a communication circuit  201 , a processing circuit  203  (including a processor  206  and memory  208  in this example) and a power supply  212 . Components of speed control circuit  250  are illustrated as communicating with each other via a data bus, although other communication interfaces can be included. Speed control circuit  250  in this example also includes a speed control  205  that can be operated by the user to control the speed control circuit  250 , for example by manual controls, touch screen, voice, and the like. 
     Processor  206  can include a GPU, CPU, microprocessor, or any other suitable processing system. The memory  208  may include one or more various forms of memory or data storage (e.g., flash, RAM, etc.) that may be used to store the calibration parameters, images (analysis or historic), point parameters, instructions and variables for processor  206  as well as any other suitable information. Memory  208  can be made up of one or more modules of one or more different types of memory, and may be configured to store data and other information as well as operational instructions that may be used by the processor  206  to speed control circuit  250 . 
     Although the example of  FIG. 2  is illustrated using processor and memory circuitry, as described below with reference to circuits disclosed herein, speed control circuit  250  can be implemented utilizing any form of circuitry including, for example, hardware, software, or a combination thereof. By way of further example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routines or other mechanisms might be implemented to make up a speed control circuit  250 . 
     Communication circuit  201  may include either or both a wireless transceiver circuit  202  with an associated antenna  214  and a wired I/O interface  204  with an associated hardwired data port (not illustrated). As this example illustrates, communications with speed control circuit  250  can include either or both wired and wireless communications circuits  201 . Wireless transceiver circuit  202  can include a transmitter and a receiver (not shown) to allow wireless communications via any of a number of communication protocols such as, for example, WiFi, Bluetooth, near field communications (NFC), Zigbee, and any of a number of other wireless communication protocols whether standardized, proprietary, open, point-to-point, networked or otherwise. Antenna  214  is coupled to wireless transceiver circuit  202  and is used by wireless transceiver circuit  202  to transmit radio signals wirelessly to wireless equipment with which it is connected and to receive radio signals as well. These RF signals can include information of almost any sort that is sent or received by speed control circuit  250  to/from other entities such as sensors  116  and vehicle systems  158 . 
     Wired I/O interface  204  can include a transmitter and a receiver (not shown) for hardwired communications with other devices. For example, wired I/O interface  204  can provide a hardwired interface to other components, including sensors  116  and vehicle systems  158 . Wired I/O interface  204  can communicate with other devices using Ethernet or any of a number of other wired communication protocols whether standardized, proprietary, open, point-to-point, networked or otherwise. 
     Power supply  212  can include one or more of a battery or batteries (such as, e.g., lithium-ion, lithium-polymer, nickel metal hydride (NiMH), nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-hydrogen (NiH 2 ), rechargeable, primary battery, etc.), a power connector (e.g., to connect to vehicle-supplied power, etc.), an energy harvester (e.g., solar cells, piezoelectric system, etc.), or include any other suitable power supply. 
     Sensors  116  may include additional sensors that may or not otherwise be included on a standard vehicle  102  with which the speed control system  200  is implemented. In the illustrated example, sensors  116  include vehicle speed sensor  222 , image sensor  224 , road sensor  226 , weather sensor  228 , and clock  230 . Additional sensors  232  can also be included as may be appropriate for a given implementation of speed control system  200 . Image sensor  224  can be implemented as a CCD, LCD or other image sensor to detect road signs, road conditions, obstacles in the road, etc. Sensor information can be processed (e.g., via processing circuit  203 ) to determine a current speed limit (e.g., via road signs), a type and severity of adverse road conditions, and so on. Road sensors  226  can include, for example, radar and lidar sensors to detect road contours and terrain, wheel-mounted accelerometers to detect wheel deflection amounts, chassis-mounted accelerometers to detect vibration amounts, and so on. Weather sensors  228  can include temperature, pressure and humidity sensors such as, for example, to detect freezing conditions. 
     Vehicle systems  158  can include any of a number of different vehicle components or subsystems used to control or monitor various aspects of the vehicle and its performance. In this example, the vehicle systems  158  include a vehicle position system  272 , a vehicle speed system  274 , and other vehicle systems  282 . Vehicle position system  272  may determine a geographic position of the vehicle, as well as its direction and speed. Vehicle position system  272  may include a global positioning satellite (GPS) system or the like. The vehicle speed system  274  may include systems such as acceleration systems, braking systems, and the like. 
     During operation, speed control circuit  250  can receive information from various vehicle sensors  116  to determine whether the speed control mode should be activated. Also, the driver may manually activate the speed control mode by operating speed control  205 . Communication circuit  201  can be used to transmit and receive information between speed control circuit  250  and sensors  116 , and speed control circuit  250  and vehicle systems  158 . Also, sensors  116  may communicate with vehicle systems  158  directly or indirectly (e.g., via communication circuit  201  or otherwise). 
     In various embodiments, communication circuit  201  can be configured to receive data and other information from sensors  116  that is used in determining whether to activate the speed control mode. Additionally, communication circuit  201  can be used to send an activation signal or other activation information to various vehicle systems  158  as part of entering the speed control mode. For example, as described in more detail below, communication circuit  201  can be used to send signals to, for example, the vehicle speed system  274 . Examples of this are described in more detail below. 
       FIG. 3  is a flowchart illustrating a process  300  for controlling the speed of a vehicle using offset speeds according to one embodiment. Referring to  FIG. 3 , the process  300  begins, at  302 . The speed control circuit  250  first determines whether the speed control mode is on, at  304 . This may include determining whether the speed control mode has been activated, for example manually by the driver using the speed control  205 . The speed control circuit  250  continues this determination until the speed control mode is activated. 
     When the speed control mode is activated, the speed control circuit  250  determines a speed limit for the section of road being traveled by the vehicle, at  306 . In some embodiments, the speed control circuit  250  determines the speed limit using images of road signs captured by the image sensor  224 . In other embodiments, the speed control circuit  250  determines the speed limit using databases that correlate the position of the vehicle with the speed limit. In yet further embodiments, the speed limit may be included in information received from vehicle positioning system  272 . After determining the speed limit, the speed control circuit  250  determines an offset from the determined speed limit. For example, in some embodiments the offset can be determined from a speed map containing offset information relative to the determined speed limit, at  308 . 
       FIG. 4  shows an example speed map  400  storing offset speeds according to one embodiment. Referring to  FIG. 4 , the speed map  400  includes a plurality of entries. Each entry associates an offset value with a respective speed limit. In the speed map  400  and  FIG. 4 , an offset of 5 mph is associated with speed limits of 5 mph, 10 mph, and 70 mph, while an offset of 10 mph is associated with the speed limit of 30 mph. In some embodiments, the speed map  400  is populated manually by the user. For example, the user may employ an application (e.g., a smart phone app) or the vehicle touch panel to populate the speed map  400  by entering his or her desired offset amounts for one or more of the plurality of speed limits. As another example, the driver may employ the speed control  205  to enter or modify entries in speed map  400 . For example, while driving at 40 mph in a 30 mph zone, the user may press a speed control button that records both the speed limit of 30 mph and the associated offset of 10 mph in the speed map  400 . In an example described below, speed map  400  may be populated by machine learning through observation of the speeds driven in different speed limit zones. In some embodiments, multiple speed maps are maintained, one for each driver of the vehicle for example, as described above. 
     The speed control circuit  250  determines an offset value based on (i) the speed limit, and (ii) the speed map  400 . The speed control circuit  250  then sets the speed of the vehicle according to the speed limit and the determined offset value, at  310 . In particular, the speed control circuit  250  determines a desired vehicle speed by adding the offset value to the determined speed limit. For example, referring to  FIG. 4 , for a speed limit of 30 mph, the offset is 10 mph, yielding a desired speed of 40 mph. Therefore, the speed control circuit  250  sets the speed of the vehicle to 40 mph. When the speed map  400  does not contain an entry for the determined speed limit, speed control circuit  250  may interpolate using a plurality of the entries in the speed map  400 . In other embodiments, when the speed map  400  does not contain an entry for the determined speed limit, the vehicle set speed can be the same as the determined speed limit. 
     The speed control circuit  250  may be implemented to occasionally determine whether the speed control mode has been deactivated, at  312 . While the speed control mode is active, the speed control circuit  250  continues to determine the speed limit, get offsets from the speed map, and set the vehicle speed according to the speed limits and offsets. When the speed control mode is deactivated, the process  300  ends, at  314 . In some embodiments, the driver may manually deactivate the speed control mode. In other embodiments, the vehicle may automatically deactivate the speed control mode such as, for example, for safety reasons. 
     In some embodiments, the speed map stores desired speeds rather than offsets.  FIG. 5  is a flowchart illustrating a process  500  for controlling the speed of a vehicle using desired speeds according to one embodiment. Referring to  FIG. 5 , the process  500  begins, at  502 . The speed control circuit  250  first determines whether the speed control mode is on, at  504 . This may include determining whether the speed control mode has been activated, for example manually by the driver using the speed control  205 . The speed control circuit  250  continues this determination until the speed control mode is activated. 
     When the speed control mode is entered, the speed control circuit  250  determines a speed limit, at  506 , for example as described above. After determining the speed limit, the speed control circuit  250  gets a desired speed from a speed map based on the determined speed limit, at  508 . 
       FIG. 6  shows an example speed map  600  storing desired speeds according to one embodiment. Referring to  FIG. 6 , the speed map  600  includes a plurality of entries. Each entry associates a desired speed with a respective speed limit. In the speed map  600  and  FIG. 6 , desired speeds of 10 mph, 15 mph, 40 mph, and 75 mph are associated with speed limits of 5 mph, 10 mph, 30 mph, and 70 mph, respectively. In some embodiments, the speed map  600  is populated manually by the user. For example, the user may employ an application (e.g., a smart phone app) or the vehicle touch panel to populate the speed map  600  by entering his or her travel speeds for one or more of the plurality of speed limits. As another example, the driver may employ the speed control  205  to enter or modify entries in speed map  600 . For example, while driving at 60 mph in a 50 mph zone, the user may press a speed control button that records both the speed limit of 50 mph and the associated desired speed of 60 mph in the speed map  600 . As noted above, speed map  600  may be populated by machine learning through observation of the speeds driven in different speed limit zones. In some embodiments, multiple speed maps are maintained, one for each driver of the vehicle, for example as described above. 
     Referring again to  FIG. 5 , the speed control circuit  250  determines a desired speed based on (i) the speed limit, and (ii) the speed map  600 . The speed control circuit  250  then sets the speed of the vehicle according to the determined desired speed, at  510 . For example, referring to  FIG. 6 , for a speed limit of 30 mph, the desired speed is 40 mph. Therefore the speed control circuit  250  sets the speed of the vehicle to 40 mph. When the speed map  600  does not contain an entry for the determined speed limit, speed control circuit  250  may interpolate using a plurality of the entries in the speed map  600 . 
     The speed control circuit  250  occasionally determines whether the speed control mode has been deactivated, at  512 . While the speed control mode is active, the speed control circuit  250  continues to determine speed limits, get desired speeds from the speed map, and set the vehicle speed to the desired speed. When the speed control mode is deactivated, the process  500  ends, at  514 . 
     In some embodiments, the speed maps described herein are populated without user intervention, such as through machine learning. In such embodiments, the speed control circuit  250  observes the speeds driven in various speed limit zones and populates the speed maps accordingly.  FIG. 7  is a flowchart illustrating a process  700  for learning a speed map according to one embodiment. Referring to  FIG. 7 , the process  700  begins, at  702 . The speed control circuit  250  first determines whether the speed control learning mode is on, at  704 . This may include determining whether the speed control learning mode has been activated, for example manually by the driver using the speed control  205 . The speed control circuit  250  continues this determination until the speed control learning mode is activated. In other embodiments, the speed control learning mode can always be on such that it is constantly adapting to the driver&#39;s behavior. 
     When the speed control learning mode is entered, the speed control circuit  250  determines a speed limit, at  706 , for example as described above regarding speed control. After determining the speed limit, the speed control circuit  250  measures the speed of the vehicle, at  708 . The speed control circuit  250  then records the speed limit and vehicle speed in the speed map, at  710 . For a speed map using offsets, the speed control circuit  250  records the speed limit and the offset in the speed map. For a speed map using desired speeds, the speed control circuit  250  records the speed limit and the desired speed in the speed map. 
     The speed control circuit  250  occasionally determines whether the speed control learning mode has been deactivated, at  712 . While the speed control learning mode is active, the speed control circuit  250  continues to determine the speed limit, measure the vehicle speed, and populate the speed map. When the speed control learning mode is deactivated, the process  700  ends, at  714 . 
     In some embodiments, the speed control circuit  250  also considers adverse conditions when setting the vehicle speed. For example, sensors  116  may determine an adverse condition for the road being traveled by the vehicle. Adverse road conditions may be determined when the road is detected to be wet, icy, rough, winding, and the like. Other adverse conditions may be considered as well, for example including traffic density, time of day, and the presence of special zones such as school zones and construction zones. 
     In some embodiments, particular adverse-conditions offsets or desired speeds may be recorded in the speed map.  FIG. 8  shows a speed map  800  using adverse-conditions offsets. Speed map  800  includes a separate column including adverse-conditions offsets for different speed limits. In embodiments using such a speed map, when adverse conditions are determined, the speed control circuit  250  uses the adverse-conditions offsets instead of the normal offsets. In other embodiments the speed map may specify adverse conditions desired speeds rather than offsets. Various sensors  116  can be used to determine whether an adverse condition exists, and if so, the type of adverse condition. For example, road sensors  226  may determine the presence of potholes or other adverse road conditions that may warrant a lower or a negative offset. As another example, a combination of weather, image and road sensors may be used to determine whether ice, snow or other conditions have led to slippery road conditions. 
     For speed maps using offsets, the offsets for adverse conditions compared to the normal offsets are generally smaller, zero, or even negative numbers. Referring again to  FIG. 8 , for speed limits of 5 mph, 10 mph, 30 mph, and 70 mph, while the normal offsets are 5 mph, 5 mph, 10 mph, and 5 mph, respectively, the offsets for adverse conditions are 0 mph, 0 mph, −5 mph, and −10 mph, respectively. So for a speed limit of 70 mph, the normal desired speed would be 75 mph, where the desired speed under adverse conditions would be 60 mph. 
     In some embodiments, different offsets are used for different adverse conditions. So for a particular speed limit, the offset for a school zone might be 0 mph, while the offset for an icy road might be −15 mph. As with normal offset values, adverse-conditions offsets can be manually entered by a driver or learned based on actual driver behavior. The speed settings for adverse-conditions can be provided as adverse-conditions offsets (as shown in  FIG. 8 ), or as actual adverse-conditions speeds. 
     In some embodiments, adverse-conditions speed settings can be factory set or factory-established not-to-exceed limits, and can be imposed such that the offsets used during detected adverse-conditions cannot exceed a predetermined amount. In further embodiments, an adverse-conditions setting can be employed such that the speed offset feature is canceled upon the detection of certain adverse-conditions. 
     As indicated above, in various embodiments the offset amounts or desired speeds can be determined for individual drivers of the vehicle. For example, in accordance with the examples provided above, various drivers of a vehicle may manually enter their desired offset amounts or the vehicle can employ machine learning or other techniques to populate a speed map based on observed driver behavior. The vehicle can use various driver identification techniques to determine an identity of the driver of the vehicle and to apply the speed map that is particular to the identified driver. For example, the vehicle can employ various biometric sensors to determine the identity of the driver. These can include, for example, image sensors for facial recognition, voice recognition, fingerprint sensors, and so on. As another example, a set of offset amounts can be correlated to a smart key used to operate the vehicle. As yet another example, a driver may be asked to enter his or her identification into the vehicle head units such as via keypad entry or speech recognition. 
     As used herein, the term component might describe a given unit of functionality that can be performed in accordance with one or more embodiments of the present application. As used herein, a component might be implemented utilizing any form of hardware, software, or a combination thereof. For example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routines or other mechanisms might be implemented to make up a component. Various components described herein may be implemented as discrete components or described functions and features can be shared in part or in total among one or more components. In other words, as would be apparent to one of ordinary skill in the art after reading this description, the various features and functionality described herein may be implemented in any given application. They can be implemented in one or more separate or shared components in various combinations and permutations. Although various features or functional elements may be individually described or claimed as separate components, it should be understood that these features/functionality can be shared among one or more common software and hardware elements. Such a description shall not require or imply that separate hardware or software components are used to implement such features or functionality. 
     Where components are implemented in whole or in part using software, these software elements can be implemented to operate with a computing or processing component capable of carrying out the functionality described with respect thereto. One such example computing component is shown in  FIG. 9 . Various embodiments are described in terms of this example-computing component  900 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the application using other computing components or architectures. 
     Referring now to  FIG. 9 , computing component  900  may represent, for example, computing or processing capabilities found within a self-adjusting display, desktop, laptop, notebook, and tablet computers. They may be found in hand-held computing devices (tablets, PDA&#39;s, smart phones, cell phones, palmtops, etc.). They may be found in workstations or other devices with displays, servers, or any other type of special-purpose or general-purpose computing devices as may be desirable or appropriate for a given application or environment. Computing component  900  might also represent computing capabilities embedded within or otherwise available to a given device. For example, a computing component might be found in other electronic devices such as, for example, portable computing devices, and other electronic devices that might include some form of processing capability. 
     Computing component  900  might include, for example, one or more processors, controllers, control components, or other processing devices. This can include a processor, and/or any one or more of the components making up hybrid vehicle  102  and its component parts, for example such as the computing component. Processor  904  might be implemented using a general-purpose or special-purpose processing engine such as, for example, a microprocessor, controller, or other control logic. Processor  904  may be connected to a bus  902 . However, any communication medium can be used to facilitate interaction with other components of computing component  900  or to communicate externally. 
     Computing component  900  might also include one or more memory components, simply referred to herein as main memory  908 . For example, random access memory (RAM) or other dynamic memory, might be used for storing information and instructions to be executed by processor  904 . Main memory  908  might also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor  904 . Computing component  900  might likewise include a read only memory (“ROM”) or other static storage device coupled to bus  902  for storing static information and instructions for processor  904 . 
     The computing component  900  might also include one or more various forms of information storage mechanism  910 , which might include, for example, a media drive  912  and a storage unit interface  920 . The media drive  912  might include a drive or other mechanism to support fixed or removable storage media  914 . For example, a hard disk drive, a solid state drive, a magnetic tape drive, an optical drive, a compact disc (CD) or digital video disc (DVD) drive (R or RW), or other removable or fixed media drive might be provided. Storage media  914  might include, for example, a hard disk, an integrated circuit assembly, magnetic tape, cartridge, optical disk, a CD or DVD. Storage media  914  may be any other fixed or removable medium that is read by, written to or accessed by media drive  912 . As these examples illustrate, the storage media  914  can include a computer usable storage medium having stored therein computer software or data. 
     In alternative embodiments, information storage mechanism  910  might include other similar instrumentalities for allowing computer programs or other instructions or data to be loaded into computing component  900 . Such instrumentalities might include, for example, a fixed or removable storage unit  922  and an interface  920 . Examples of such storage units  922  and interfaces  920  can include a program cartridge and cartridge interface, a removable memory (for example, a flash memory or other removable memory component) and memory slot. Other examples may include a PCMCIA slot and card, and other fixed or removable storage units  922  and interfaces  920  that allow software and data to be transferred from storage unit  922  to computing component  900 . 
     Computing component  900  might also include a communications interface  924 . Communications interface  924  might be used to allow software and data to be transferred between computing component  900  and external devices. Examples of communications interface  924  might include a modem or softmodem, a network interface (such as an Ethernet, network interface card, WiMedia, IEEE 802.XX or other interface). Other examples include a communications port (such as for example, a USB port, IR port, RS232 port Bluetooth® interface, or other port), or other communications interface. Software/data transferred via communications interface  924  may be carried on signals, which can be electronic, electromagnetic (which includes optical) or other signals capable of being exchanged by a given communications interface  924 . These signals might be provided to communications interface  924  via a channel  928 . Channel  928  might carry signals and might be implemented using a wired or wireless communication medium. Some examples of a channel might include a phone line, a cellular link, an RF link, an optical link, a network interface, a local or wide area network, and other wired or wireless communications channels. 
     In this document, the terms “machine-readable storage medium,” “computer program medium,” and “computer usable medium” are used to generally refer to transitory or non-transitory media. Such media may be, e.g., memory  908 , storage unit  920 , media  914 , and channel  928 . These and other various forms of computer program media or computer usable media may be involved in carrying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied on the medium, are generally referred to as “computer program code” or a “computer program product” (which may be grouped in the form of computer programs or other groupings). When executed, such instructions might enable the computing component  900  to perform features or functions of the present application as discussed herein. 
     It should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described. Instead, they can be applied, alone or in various combinations, to one or more other embodiments, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present application should not be limited by any of the above-described exemplary embodiments. 
     Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing, the term “including” should be read as meaning “including, without limitation” or the like. The term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof. The terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known.” Terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time. Instead, they should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future. 
     The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. The use of the term “component” does not imply that the aspects or functionality described or claimed as part of the component are all configured in a common package. Indeed, any or all of the various aspects of a component, whether control logic or other components, can be combined in a single package or separately maintained and can further be distributed in multiple groupings or packages or across multiple locations. 
     Additionally, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration.