System and method for adjusting autonomous emergency braking in response to change in vehicle mass

Abstract

An autonomous emergency braking system includes a sensor that generates a collision risk signal indicative of an object in a path of travel of a vehicle, and a controller. The controller determines whether there is an indication of a mass of the vehicle and, if so, adjusts a default deceleration value corresponding to a predetermined deceleration rate of the vehicle in response to the mass to obtain a mass-adjusted deceleration value. The controller establishes a continuous time to generate a first brake command and a second brake command to the engine or the brake controller or to increase a braking force for the first brake command and the second brake command in response to a deceleration value of the mass adjustment, the first brake command and the second brake command are configured to cause the vehicle to decelerate at a first deceleration rate and a second deceleration rate, the second rate being greater than the first rate. A first brake command and a second brake command are generated in response to the collision risk signal.

Description

Technical Field

[0001] The present disclosure relates to autonomous emergency braking systems for vehicles. In particular, the present disclosure relates to systems and methods for adjusting autonomous emergency braking of a vehicle in response to changes in vehicle mass. Background Art

[0002] Conventional vehicles increasingly employ advanced driver assistance systems (ADAS) that take control of various vehicle systems or supplement operator control based on conditions associated with the vehicle, the road surface, and objects around the vehicle, including pedestrians, other vehicles, and road infrastructure. Exemplary systems include adaptive cruise control systems, anti-lock braking systems (ABS), and collision avoidance systems, including, for example, blind spot monitoring, lane departure warning, lane keeping, and lane change assistance systems. Another conventional system is known as autonomous emergency braking (AEB) and may be implemented as a standalone system or in accordance with one of the above systems. In AEB, emergency braking is applied when certain conditions are detected to slow or stop the movement of the vehicle. When conditions requiring braking are detected, a controller generates one or more commands that cause the application of wheel brakes.

[0003] In some vehicles (such as tractor-trailer, etc.), the load of the vehicle and therefore the total mass of the vehicle can vary significantly. The tractor can be operated, for example, without any attached trailer (i.e., a towing cable car configuration). Alternatively, the tractor can have one or more trailers attached, each of which can be unloaded, partially loaded, or fully loaded. Because the load on the vehicle and the total mass of the vehicle vary significantly, the time, distance, and deceleration level required to stop the tractor and any attached trailer from any given speed also vary significantly. However, conventional AEB systems typically assume a constant predetermined deceleration level for the vehicle and use this predetermined deceleration level to determine when to initiate the brakes and / or braking force in the vehicle. If the predetermined deceleration level assumes a lightly loaded vehicle, the AEB system in the vehicle may not be able to stop the vehicle in sufficient time to prevent a collision when the vehicle is more heavily loaded. If the predetermined deceleration level assumes a heavily loaded vehicle, the AEB system in the vehicle can stop the vehicle away from any potential collision when the vehicle is more lightly loaded. Therefore, conventional AEB systems typically set the predetermined deceleration level at a compromise value between the value for the least loaded vehicle and the value for the most loaded vehicle, thereby sacrificing some stopping and collision avoidance performance to avoid stopping the vehicle too quickly.

[0004] The inventors herein have recognized a need for an autonomous emergency braking system and method for a vehicle that would minimize and / or eliminate one or more of the above-mentioned drawbacks. Summary of the invention

[0005] The present disclosure relates to autonomous emergency braking systems for vehicles. In particular, the present disclosure relates to systems and methods for adjusting autonomous emergency braking of a vehicle in response to changes in vehicle mass.

[0006] An embodiment of an autonomous emergency braking system for a vehicle includes a sensor configured to generate a collision risk signal indicating an object in a path of travel of the vehicle. The system further includes an autonomous emergency braking controller. The autonomous emergency braking controller is configured to determine whether there is an indication of the mass of the vehicle, and if there is an indication of the mass of the vehicle, adjust a first deceleration value corresponding to a predetermined deceleration rate of the vehicle in response to the mass of the vehicle to obtain a second deceleration value. The autonomous emergency braking controller is further configured to establish one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command in response to the second deceleration value. The first braking command is configured to cause the vehicle to decelerate at a first deceleration rate. The autonomous emergency braking controller is further configured to establish a corresponding one of a second time later than the first time and a second braking force greater than the first braking force for generating a second braking command to one of the engine controller and the brake controller in response to the second deceleration value. The second braking command is configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate. The autonomous emergency braking controller is further configured to generate the first braking command and the second braking command in response to the collision risk signal.

[0007] One embodiment of a method for autonomous emergency braking in a vehicle includes: determining whether there is an indication of the mass of the vehicle; and if there is an indication of the mass of the vehicle, adjusting a first deceleration value corresponding to a predetermined deceleration rate of the vehicle in response to the mass of the vehicle to obtain a second deceleration value. The method further includes establishing one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command in response to the second deceleration value. The first braking command is configured to cause the vehicle to decelerate at a first deceleration rate. The method further includes establishing a corresponding one of a second time later than the first time for generating a second braking command to one of an engine controller and a brake controller and a second braking force greater than the first braking force for the second braking command in response to the second deceleration value. The second braking command is configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate. The method further includes generating the first braking command and the second braking command in response to a collision risk signal indicating an object in the path of travel of the vehicle.

[0008] An embodiment of an article of manufacture includes a non-transitory computer storage medium having encoded thereon a computer program that, when executed by a controller, implements autonomous emergency braking in a vehicle. The computer program includes code for determining whether there is an indication of vehicle mass, and if there is an indication of vehicle mass, adjusting a first deceleration value corresponding to a predetermined deceleration rate of the vehicle in response to the vehicle mass to obtain a second deceleration value. The computer program further includes code for establishing one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command in response to the second deceleration value. The first braking command is configured to cause the vehicle to decelerate at a first deceleration rate. The computer program further includes code for establishing one of a second time later than the first time and a second braking force greater than the first braking force for generating a second braking command to one of an engine controller and a brake controller in response to the second deceleration value. The second braking command is configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate. The computer program further includes code for generating the first braking command and the second braking command in response to a collision risk signal indicating an object in a path of travel of the vehicle.

[0009] Systems and methods for autonomous emergency braking in a vehicle according to the teachings disclosed herein are advantageous over conventional systems and methods. Specifically, the systems and methods adjust a predetermined deceleration value associated with a vehicle based on changes in load and mass on the vehicle, and control the timing of cascaded braking commands (and other actions) and / or the force of the braking commands in response to the adjusted value to optimize braking of the vehicle regardless of changes in load and mass on the vehicle.

[0010] The foregoing and other aspects, features, details, utilities and advantages of the present teachings will become apparent from reading the following description and claims, and from reviewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic diagram of a tractor-trailer incorporating one embodiment of a system for autonomous emergency braking according to the teachings set forth herein.

[0012] Figure 2 is a flow chart illustrating several steps in one embodiment of a method of performing autonomous emergency braking in a vehicle according to the teachings set forth herein. DETAILED DESCRIPTION

[0013] Referring now to the drawings, wherein like reference numerals are used to identify like parts throughout the various views, Figure 1A vehicle is illustrated, and in particular a tractor-trailer 10 is illustrated. The tractor-trailer 10 (also referred to as a semi-trailer) includes a truck or tractor 12 and one or more trailers 141 ... 142. N The tractor 12 includes a power unit, such as an internal combustion engine 16, and a steered axle 18 and a driven axle 20, each of which supports one or more wheels 22 at either end. N The tractor-trailer 10 is configured to store cargo and is removably coupled to the tractor 12. Each trailer 14 is supported on one or more trailer axles 24, each of which may support one or more wheels 20 at either end. Although a pair of trailers 14 is shown in the illustrated embodiment, it should be understood that the number of trailers 14 attached to the tractor 12 may vary. According to the present teachings, the tractor-trailer 10 may further include one or more advanced driver assistance systems 26, which are configured to implement autonomous emergency braking (AEB) of the tractor-trailer 10 under certain conditions. The system 26 may include, for example, a collision avoidance system, and may include an engine braking system 28, a wheel braking system 30, one or more sensors 32, an operator interface 34, and an autonomous emergency braking (AEB) controller 36, which communicate with each other via a conventional vehicle communication bus such as a controller area network (CAN) or another communication medium such as a power line communication (PLC). In some embodiments, the elements of system 26 may communicate over the bus using the Society of Automotive Engineers industry standard (SAE) J1939 communication protocol.

[0014] An engine braking system 28 is provided to selectively reduce the torque generated by the engine 16 to brake the tractor-trailer 10. The system 28 may include an engine controller 38 that generates signals in response to braking commands from the AEB controller 36 to control valves that regulate the air and / or fuel delivered to the cylinders in the engine 16 to stop the combustion process and valves for exhausting compressed air from the cylinders to establish a mechanical resistance on the tractor-trailer 10 and brake the tractor-trailer 10. The engine controller 38 may include a programmable microprocessor or microcontroller, or may include an application specific integrated circuit (ASIC). The engine controller 38 may include a central processing unit (CPU) and a memory. The engine controller 38 may also include an input / output (I / O) interface through which the engine controller 38 may receive a plurality of input signals and send a plurality of output signals. The input signals may include braking commands from the AEB controller 36. The output signals may include signals for controlling the above-mentioned valves in the engine 16.

[0015] The wheel brake system 30 is configured to brake the wheels 22 on the tractor 12 and trailer 14 in order to slow or stop the movement of the tractor-trailer 10. The system 30 may include a brake controller 40 configured to generate a signal for controlling a valve in a fluid circuit that regulates the delivery of fluid pressure from a fluid source of the fluid circuit to a brake actuator for a disc brake or drum brake associated with each wheel 22 on the tractor 12 and trailer 14. According to the teachings disclosed herein, the controller 40 may also generate such signals in response to a brake command from the AEB controller 36. The brake controller 40 may again include a programmable microprocessor or microcontroller or may include an application specific integrated circuit (ASIC). The brake controller 40 may include a central processing unit (CPU) and a memory. The brake controller 40 may also include an input / output (I / O) interface through which the brake controller 40 may receive a plurality of input signals and send a plurality of output signals. The input signal may include a brake command from the AEB controller 36. The output signals may include signals for controlling the aforementioned valves in the fluid circuits.The brake controller 40 may be configured with suitable programming instructions (ie, software or computer program) to implement anti-lock braking (ABS) and electronic stability control functions.

[0016] Sensors 32 are provided to identify objects within a defined field of view. The sensors 32 may include radar (radio detection and ranging) sensors, but may also include lidar (light detection and ranging) sensors, cameras, or other sensors. In the illustrated embodiment, the sensors 32 are located in front of the tractor-trailer 12 and identify objects in front of the tractor-trailer 10. However, it should be understood that the sensors 32 may be located in different locations on the tractor-trailer 10, including on the side of the vehicle (e.g., for blind spot monitoring, lane departure warning, and lane change assist systems) or at the rear of the vehicle (e.g., for a parking assist system). Each sensor 32 generates a signal indicative of an object within the field of view of the sensor 32, and the signal is sent to the AEB controller 36.

[0017] The operator interface 34 provides a means for alerting the vehicle operator of the initiation of autonomous emergency braking. The interface 34 may also provide a means for alerting the vehicle operator of other aspects of autonomous emergency braking, such as the location of objects in the path of travel of the tractor-trailer 10, etc. (e.g., by providing a warning when an object is too close to the tractor-trailer 10). The interface 34 may include light emitters such as light emitting diodes, sound emitters such as speakers, and / or tactile actuators to communicate visual, audio, and / or tactile alerts to the vehicle operator. In the case of visual alerts, different information may be conveyed through differences in color, differences in intensity, differences in the number of lights, and differences in the activation pattern of the lights. In the case of audio alerts, different information may be conveyed through differences in the type of sound produced, differences in volume, and differences in the sound pattern. In the case of tactile alerts, different information may be conveyed through differences in the length, intensity, or pattern of vibrations.

[0018] An autonomous emergency braking (AEB) controller 36 determines whether an object detected by the sensor 32 necessitates a warning to the vehicle operator or some other action (including autonomous control of the tractor-trailer 10, such as automatic emergency braking, etc.). The AEB controller 36 may include a programmable microprocessor or microcontroller, or may include an application specific integrated circuit (ASIC). The AEB controller 36 may include a central processing unit (CPU) 42 and a memory 44. The AEB controller 36 may also include an input / output (I / O) interface 46 through which the AEB controller 36 may receive a plurality of input signals and send a plurality of output signals. The input signals may include signals from the sensor 32 indicating the presence of an object within the field of view of the sensor 32 and signals from the operator interface 34. The output signals may include signals for controlling the engine braking system 28, the wheel braking system 30, and the operator interface 34. Although a single AEB controller 36 is shown in the illustrated embodiment, it should be understood that the functionality of the AEB controller 36 may be divided into a plurality of sub-controllers including separate controllers on the tractor 12 and the trailer 14.

[0019] See now Figure 2In accordance with the present teachings, the AEB controller 36 may be configured with appropriate programming instructions (i.e., software or computer program) to implement several steps in a method of autonomous emergency braking in a tractor-trailer 10. The method may begin at step 48 of determining whether the disclosed control method that takes into account the mass of the tractor-trailer 10 has been enabled. Use of the disclosed control method may be optional on any given tractor-trailer 10 and may be enabled by a vehicle operator through a fleet manager for the tractor-trailer 10 (e.g., by pre-programming the AEB controller 36 prior to operation of the tractor-trailer 10 (via the operator interface 34 or in another manner) or by wirelessly transmitting a signal through a telematics system in the tractor-trailer 10), or in response to various conditions detected by various sensors on the tractor-trailer 10 associated with the operation of the tractor-trailer 10 or the operating environment for the tractor-trailer 10 (e.g., by input via the operator interface 34). A flag stored in a memory (e.g., memory 44) may be used to indicate whether use of the disclosed control method has been enabled or disabled, and the AEB controller 36 may access the memory 44 to retrieve the flag and compare it to a predetermined value indicating that use of the control method has been enabled. If use of the control method has been disabled, the method may end. If use of the control method has been enabled, the method may proceed to a subsequent step.

[0020] In step 50, the AEB controller 36 determines if there is an indication of the mass of the tractor-trailer 10. The AEB controller 36 may be configured to search for and receive various signals on the vehicle communication bus that are indicative of the mass of the tractor-trailer 10. These signals may be generated, for example, by load sensors (not shown) on the tractor-trailer 10 (including on the kingpin or axles 18, 20, 24 of the tractor-trailer 10), by the engine controller 38 or transmission controller responsive to input torque relative to the speed of the tractor-trailer 10, and / or by the brake controller 40 responsive to brake pressure (when ABS is not implemented). According to one aspect of the disclosed system, the AEB controller 36 may be configured to prioritize between the signals by first searching for the signals most likely to produce an accurate indication of the mass of the tractor-trailer 10 (e.g., signals produced by axle-mounted load sensors), and if the signals most likely to produce an accurate indication of the mass of the tractor-trailer 10 are not present on the communication bus, then only subsequently searching for signals less likely to produce an accurate indication of the mass of the tractor-trailer 10. In one embodiment, the AEB controller 36 may be configured to search for the presence of a signal on the communication bus that corresponds to one of Suspicious Parameter Number (SPN) 1760 and SPN 417 of the Society of Automotive Engineers J1939 communication protocol. SPN 1760 provides a value indicative of the total weight of the tractor 12 and all attached trailers 14. SPN 417 provides a value indicative of the total weight of the tractor 12 and all attached trailers 14, where there is an onboard scale on the tractor-trailer 10. If a signal corresponding to a preferred value of SPN 1760 and SPN 417 is not present, the AEB controller 36 may be configured to search for the presence of a signal corresponding to the other of SPN 1760 and SPN 417. Figure 2 In the illustrated embodiment, the AEB controller 36 first searches for the presence of a signal corresponding to SPN 1760, and if that signal is not found, searches for the presence of a signal corresponding to SPN 417. However, it should be understood that the order may be reversed, and the AEB controller 36 may search for other signals indicative of quality in addition to or in lieu of one or both of the signals corresponding to SPN 1760 and SPN 417 and in a different order.

[0021] In the absence of an indication of the mass of the tractor-trailer 10, the AEB controller 36 is configured to implement autonomous emergency braking (whenever required) based on a predetermined or default deceleration value for the tractor-trailer 10 (corresponding to a predetermined rate of deceleration of the tractor-trailer 10). The predetermined deceleration value may be stored in a memory, such as the memory 44 of the AEB controller 36. As described above, the deceleration value is typically set to a value that attempts to balance the ability of the tractor-trailer 10 to decelerate when heavily loaded (in which case deceleration occurs more slowly) and when lightly loaded (in which case deceleration occurs more quickly), and therefore may not fully mitigate the collision risk of a heavily loaded vehicle, while also sacrificing the performance of a lightly loaded vehicle, which will stop earlier than necessary. However, the predetermined deceleration value may alternatively be set to a value indicative of a minimally loaded tractor 12 (i.e., a tractor without any trailers 14 attached) when deceleration is expected to occur relatively quickly, or to a value indicative of a maximally loaded tractor 12 (i.e., a tractor 12 with one or more trailers 14 and carrying the maximum possible load of the tractor 12) when deceleration is expected to occur relatively slowly.

[0022] When the indication of the mass of the tractor-trailer 10 is present, the method may continue with step 52 of adjusting the predetermined deceleration value in response to the mass of the vehicle to obtain a mass-adjusted deceleration value. Step 52 may include a number of sub-steps 54, 56. In sub-step 54, the AEB controller 36 may determine a final load factor (FLF) in response to the mass of the tractor-trailer 10. According to one embodiment, if the mass of the tractor-trailer 10 satisfies a predetermined condition relative to a first predetermined mass (e.g., 5000 Kg), the AEB controller 36 assigns a first value to the final load factor. For example, if the mass of the tractor-trailer 10 is less than the first predetermined mass, the AEB controller 36 may assign the first value to the final load factor. If the mass of the tractor-trailer 10 satisfies a predetermined condition relative to a second predetermined mass (e.g., 36000 Kg), the AEB controller 36 assigns a second value to the final load factor. For example, if the mass of the tractor-trailer 10 is greater than the second predetermined mass, the AEB controller 36 may assign the second value to the final load factor. If the predetermined condition is not met (e.g., the mass is not less than the first predetermined mass and not greater than the second predetermined mass), the AEB controller 36 may calculate the final load factor according to a predetermined formula. According to one embodiment, the AEB controller 36 uses the formula to adjust the default load factor (DLF) in response to the mass of the vehicle to obtain the final load factor. In one embodiment, the default load factor is set to a value corresponding to the tractor 12 without any trailer 14. In such an embodiment, the AEB controller 36 may calculate the final load factor according to the following formula:

[0023]

[0024] Wherein, FLF is the final load factor, DLF is the default load factor, M is the mass of the tractor-trailer 10, UB and LB are the upper limit (e.g., 36000Kg) and lower limit (e.g., 5000Kg) of the mass of the tractor-trailer 10 covered by the system 26, respectively, and BLF and CLF are the minimum possible load factor and the maximum possible load factor allowed by the system 26, respectively. If the mass M of the tractor-trailer 10 is less than LB or greater than UB, the final load factor FLF will be no greater than the default load factor DLF and no less than BLF. In another embodiment, the default load factor is set to a value corresponding to the tractor 12 towing the maximum load of the tractor 12. In such an embodiment, the AEB controller 36 can calculate the final load factor according to the following formula:

[0025]

[0026] If the mass M of the tractor-trailer 10 is less than LB or greater than UB, the final load factor FLF will be no greater than CLF and no less than DLF. In sub-step 56, the AEB controller 36 applies the final load factor to the predetermined deceleration value to obtain a mass-adjusted deceleration value. In one embodiment, the AEB controller 36 determines the mass-adjusted deceleration value according to the following formula:

[0027] MADV=FLF*PDV

[0028] where MADV is the mass adjusted deceleration value, and PDF is the predetermined deceleration value.

[0029] According to one aspect of the teachings disclosed herein, the mass-adjusted deceleration value obtained in step 52 can be independent of brake pressure. There are various conventional systems that adjust brake control based on various vehicle and environmental operating conditions. Many of these conventional systems perform basic control based at least in part on measured brake pressure. However, for commercial vehicles such as tractor-trailer 10 that employ pneumatic brake systems, measured brake pressure is an unreliable indicator of braking capacity and efficiency due to wear on various vehicle components including brake friction pads and tires. According to another aspect of the teachings disclosed herein, the adjustment from the default deceleration to the mass-adjusted deceleration value can have a non-linear relationship with changes in the mass of the tractor-trailer 10. In particular, the final load factor can be calculated in such a way that changes in the final load factor (and, therefore, the mass-adjusted deceleration value) do not occur linearly with changes in the mass of the tractor-trailer 10 to better approximate the potential non-linear relationship between vehicle stopping distance / time and vehicle mass.

[0030] See again Figure 2, the method may continue at step 58 by establishing, in response to the mass-adjusted deceleration value (or, if there is no indication of the mass of the tractor-trailer in step 50, in response to the predetermined deceleration value), a cascade of values ​​associated with a plurality of actions associated with autonomous emergency braking of the tractor-trailer 10. According to one aspect of some embodiments of the systems and methods disclosed herein, a change in the mass of the tractor-trailer 10 affects a series of coordinated actions associated with autonomous emergency braking, and each action is affected in a similar manner. In one embodiment, the AEB controller 36 establishes a first time t1 for generating an alert to an operator of the tractor-trailer 10 regarding the initiation of autonomous emergency braking, a second time t2 later than the first time, and a third time t3 later than the second time, the first time t1 for generating a first braking command to one or both of the engine controller 38 and the brake controller 40, and the third time t3 for generating a second braking command to one or both of the engine controller 38 or the brake controller 40. In another embodiment, the AEB controller 36 establishes a first braking force F1 for a first braking command and a second braking force F2 that is greater than the first braking force F1 or the second braking command. The first braking command is configured to cause the tractor-trailer 10 to decelerate at a first deceleration rate, while the second braking command is configured to cause the tractor-trailer 10 to decelerate at a second deceleration rate that is greater than the first deceleration rate. The cascade value of this series of coordinated actions can be affected by the mass-adjusted deceleration value in a similar manner. For example, in order to s To stop the tractor-trailer 10, the times t1, t2, and t3 may be preset to be respectively at time t s If the tractor-trailer 10 is heavily loaded, the mass-adjusted deceleration value will reflect that braking performance will be reduced due to the greater mass of the tractor-trailer 10. In the event that the mass-adjusted deceleration value reflects the expectation that braking performance will be reduced to 70% of the expected performance due to the increased mass of the tractor-trailer 10, the AEB controller 36 may establish the braking performance at time t respectively in response to the mass-adjusted deceleration value. s The method may continue with steps 60 , 62 , 64 by responding to any collision risk signal from sensor 32 to generate a warning to the vehicle operator at time t1 , a first braking command at time t2 , and a second braking command at time t3 .

[0031] In some embodiments, the method may include additional steps to account for brake activation delays that may occur in commercial vehicle systems that employ pneumatic brake systems. While these delays may be accounted for to some extent by adjusting some pre-programmed values ​​in the AEB controller 36, the method does not account for variations in activation delays between individual vehicles. Therefore, according to one embodiment, the method may continue with steps 66, 68: starting a timer when the first braking command or the second braking command is generated, and recording the time indicated by the timer to establish the deceleration time when a predetermined condition indicating an amount of deceleration in the tractor-trailer is met (alternatively, as opposed to using the braking command generated by the AEB controller 36, a braking command signal from another system (e.g., an adaptive cruise control or stability control system) may be used to start the timer). For example, the AEB controller 36 may be configured to record the time at which the brake controller 40 generates an indication that a predetermined deceleration level (e.g., 1 m / s 2 ) or the time when the brake controller 40 generates a signal indicating that braking has been activated (e.g., when the brake pressure has reached a predetermined pressure threshold at which a stop light on the vehicle is illuminated). In other embodiments, the time indicated by the timer may be recorded at multiple times (e.g., when the brake controller 40 generates a signal indicating that a predetermined deceleration level has been exceeded, and when the brake controller 40 generates a signal indicating that braking has been initiated), and the times are averaged to obtain the deceleration time. In other embodiments, the time of the same event occurring during consecutive braking actions in the tractor-trailer 10 may be recorded multiple times, and the AEB controller 36 may predict the time of the same event occurring during the next braking action in the tractor-trailer 10 based on a trend of the recorded times, and establish the deceleration time in response to the predicted time. The method may then continue with steps 70, 72: adjusting the mass-adjusted deceleration value in response to the deceleration time to obtain a time-adjusted deceleration value, and adjusting the times t1, t2, t3 in response to the time-adjusted deceleration value for generating a warning to the vehicle operator and the first and second braking commands and / or the forces F1 and F2 for the first and second braking commands.

[0032] Systems and methods for autonomous emergency braking in a vehicle according to the teachings disclosed herein are advantageous over conventional systems and methods. Specifically, the systems and methods adjust a predetermined deceleration value associated with a vehicle based on changes in load and mass on the vehicle, and control the timing of cascaded braking commands (and other actions) and / or the force of the braking commands in response to the adjusted value to optimize braking of the vehicle regardless of changes in load and mass on the vehicle.

[0033] Although the present invention has been shown and described with reference to one or more specific embodiments thereof, it will be appreciated by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. For example, the overmolding and clamping techniques disclosed herein are not limited to wheel speed sensors, but may also be used for other sensors having similar mounting arrangements, including transmission sensors and crankshaft sensors.

Claims

1. An autonomous emergency braking system for a vehicle, comprising: a sensor configured to generate a collision risk signal indicative of an object in a path of travel of the vehicle; as well as, An autonomous emergency braking controller, the autonomous emergency braking controller being configured to: determining whether there is an indication of a mass of the vehicle; if there is an indication of the mass of the vehicle, adjusting a first deceleration value corresponding to a predetermined rate of deceleration of the vehicle in response to the mass of the vehicle to obtain a second deceleration value; establishing, in response to the second deceleration value, one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command, the first braking command being configured to cause the vehicle to decelerate at a first deceleration rate; and establishing a corresponding one of a second time later than the first time and a second braking force greater than the first braking force for generating a second braking command to one of the engine controller and the brake controller, the second braking command configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate; as well as, The first braking command and the second braking command are generated in response to the collision risk signal.

2. The autonomous emergency braking system according to claim 1, wherein: The autonomous emergency brake controller is further configured, in determining whether there is an indication of a mass of the vehicle: determining whether a first signal indicative of a mass of the vehicle is present on a vehicle communication bus; as well as, If the first signal is not present on the vehicle communication bus, it is determined whether a second signal indicative of a mass of the vehicle is present on the vehicle communication bus.

3. The autonomous emergency braking system according to claim 1, wherein: The autonomous emergency braking controller is further configured, in adjusting the first deceleration value, determining a final load factor responsive to the mass of the vehicle; as well as, The final load factor is applied to the first deceleration value to obtain the second deceleration value.

4. The autonomous emergency braking system according to claim 3, wherein: If the mass of the vehicle is less than a first predetermined mass, a first value is assigned to the final load factor, if the mass of the vehicle is greater than a second predetermined mass, a second value is assigned to the final load factor, and if the mass of the vehicle is not less than the first predetermined mass and not greater than the second predetermined mass, the final load factor is calculated according to a predetermined formula.

5. The autonomous emergency braking system according to claim 3, wherein: The vehicle includes a tractor, and the autonomous emergency brake controller is further configured to, in determining the final load factor, adjust a default load factor in response to the mass of the vehicle to obtain the final load factor, the default load factor being set to a value corresponding to one of the tractor without any trailer and the tractor towing a maximum load.

6. The autonomous emergency braking system according to claim 1, wherein: The autonomous emergency braking controller is configured to adjust the first deceleration value independently of brake pressure to obtain the second deceleration value.

7. The autonomous emergency braking system according to claim 1, wherein: The difference between the second deceleration rate and the first deceleration rate has a non-linear relationship with a change in the amount of mass of the vehicle.

8. The autonomous emergency braking system according to claim 1, wherein: The autonomous emergency braking controller is also configured to: starting a timer when one of the first braking command and the second braking command is generated; recording a time on the timer when a predetermined condition indicative of an amount of deceleration of the vehicle is satisfied to establish a deceleration time; adjusting the second deceleration value in response to the deceleration time to obtain a third deceleration value; and, One of the first time and the first braking force and a corresponding one of the second time and the second braking force are adjusted in response to the third deceleration value.

9. The autonomous emergency braking system according to claim 1, wherein: The autonomous emergency braking controller is further configured to establish a third time prior to the first time in response to the second deceleration value, the third time being used to generate an alert to an operator of the vehicle regarding brake initiation.

10. A method for autonomous emergency braking in a vehicle, comprising: determining whether there is an indication of a mass of the vehicle; if there is an indication of the mass of the vehicle, adjusting a first deceleration value corresponding to a predetermined rate of deceleration of the vehicle in response to the mass of the vehicle to obtain a second deceleration value; establishing, in response to the second deceleration value, one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command, the first braking command being configured to cause the vehicle to decelerate at a first deceleration rate; and establishing a corresponding one of a second time later than the first time and a second braking force greater than the first braking force for generating a second braking command to one of the engine controller and the brake controller, the second braking command configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate; as well as, The first and second braking commands are generated in response to a collision risk signal indicative of an object in a path of travel of the vehicle.

11. The method according to claim 10, wherein: Determining whether there is an indication of mass of the vehicle includes: determining whether a first signal indicative of a mass of the vehicle is present on a vehicle communication bus; and, If the first signal is not present on the vehicle communication bus, it is determined whether a second signal indicative of a mass of the vehicle is present on the vehicle communication bus.

12. The method according to claim 10, wherein: Adjusting the first deceleration value includes: determining a final load factor responsive to the mass of the vehicle; and, The final load factor is applied to the first deceleration value to obtain the second deceleration value.

13. The method according to claim 12, wherein: If the mass of the vehicle is less than a first predetermined mass, a first value is assigned to the final load factor, if the mass of the vehicle is greater than a second predetermined mass, a second value is assigned to the final load factor, and if the mass of the vehicle is not less than the first predetermined mass and not greater than the second predetermined mass, the final load factor is calculated according to a predetermined formula.

14. The method according to claim 12, wherein: The vehicle includes a tractor, and determining the final load factor includes adjusting a default load factor in response to a mass of the vehicle to obtain the final load factor, the default load factor being set to a value corresponding to one of the tractor without any trailer and the tractor towing a maximum load.

15. The method according to claim 10, wherein: Adjusting the first deceleration value to obtain the second deceleration value occurs independently of brake pressure.

16. The method according to claim 10, wherein: The difference between the second deceleration rate and the first deceleration rate has a non-linear relationship with a change in the amount of mass of the vehicle.

17. The method according to claim 10, further comprising: starting a timer when one of the first braking command and the second braking command is generated; recording a time on the timer when a predetermined condition indicative of an amount of deceleration of the vehicle is satisfied to establish a deceleration time; adjusting the second deceleration value in response to the deceleration time to obtain a third deceleration value; and, One of the first time and the first braking force and a corresponding one of the second time and the second braking force are adjusted in response to the third deceleration value.

18. The method according to claim 10, further comprising: A third time prior to the first time is established in response to the second deceleration value, the third time being used to generate a warning to an operator of the vehicle regarding brake initiation.

19. An article of manufacture comprising: A non-transitory computer storage medium having encoded thereon a computer program that, when executed by a controller, implements autonomous emergency braking in a vehicle, the computer program comprising code for: determining whether there is an indication of a mass of the vehicle; if there is an indication of the mass of the vehicle, adjusting a first deceleration value corresponding to a predetermined rate of deceleration of the vehicle in response to the mass of the vehicle to obtain a second deceleration value; as well as, establishing, in response to the second deceleration value, one of a first time for generating a first braking command to one of an engine controller and a brake controller and a first braking force for the first braking command, the first braking command being configured to cause the vehicle to decelerate at a first deceleration rate; and establishing a corresponding one of a second time later than the first time and a second braking force greater than the first braking force for generating a second braking command to one of the engine controller and the brake controller, the second braking command configured to cause the vehicle to decelerate at a second deceleration rate greater than the first deceleration rate; as well as, The first and second braking commands are generated in response to a collision risk signal indicative of an object in a path of travel of the vehicle.

20. The article of claim 19, wherein: The computer program further comprises code for: When one of the first braking command and the second braking command is generated, starting a timer; recording a time on the timer to establish a deceleration time when a predetermined condition indicative of an amount of deceleration of the vehicle is satisfied; adjusting the second deceleration value in response to the deceleration time to obtain a third deceleration value; as well as, One of the first time and the first braking force and a corresponding one of the second time and the second braking force are adjusted in response to the third deceleration value.

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