Abstract: A vehicle brake systems (10) is provided which compensates for brake pedal feel variation to provide enhanced braking feel. The brake system (10) includes a brake pedal (18), a wheel sensor (20), and a database (16) for storing target accelerations and torque to pressure parameters. The brake systems (10) may employ a friction brakes (26) and regenerative brakes (29). The brake system further includes a controllers (12) for controlling the amount of braking, including the friction brake actuator (24). The controller (12) determines brake acceleration caused by braking torque and determines a target acceleration based on the driver commanded input. The controller (12) also determines a brake acceleration error as the difference between the target acceleration and the brake acceleration. The controller adjusts the torque-related parameter to reduce the brake acceleration error by adjusting the braking torque generated by the friction brake actuator to compensate for brake torque variation.

Abstract: A vehicle brake system 10 is provided which compensates for brake pedal feel variation to provide enhanced braking feel. The brake system 10 includes a brake pedal 18, a wheel speed sensor 20, and a database 16 for storing target accelerations and torque to pressure parameters. The brake system 10 may employ a friction brakes 26 and regenerative brakes 29. The brake system further includes a controller 12 for controlling the amount of braking, including the friction brake actuator 24. The controller 12 determines brake acceleration caused by braking torque and determines a target acceleration based on the driver commanded input. The controller 12 also determines a brake acceleration error as the difference between the target acceleration and the brake acceleration. The controller adjusts the torque-related parameter to reduce the brake acceleration error by adjusting the braking torque generated by the friction brake actuator to compensate for brake torque variation.

Abstract: A method and system that responds to non-propulsive needs of a hybrid vehicle by setting at least two thresholds related to engine support: one threshold to keep a running engine ON and a another threshold to turn the engine ON from an OFF state.

Abstract: A system and method for braking a towed conveyance. In one embodiment, a system is provided for use on a trailer (102) having an axle assembly (108). The system (100) includes a motor controller (124), a pair of electric motor/generators (120), a battery (122), a battery controller (126), and sensors (128). Controller (124) monitors the yaw rate of trailer (102) by use of sensors (128). Based upon the monitored yaw rate, controller (124) selectively activates motor/generators (120) which provide a regenerative braking torque to axle assembly (108), thereby braking trailer (102) and generating electrical energy which may be used to recharge battery (122).

Abstract: A brake assembly 12 for use within an electric vehicle 10 and which allows the vehicle 10 to be selectively decelerated in substantially the same manner as is an internal combustion engine type vehicle upon the release of an accelerator pedal member 18 or the depression of a brake member 20.

Abstract: The present invention provides an improved method and system to monitor vehicle operation state and operator requests. The invention combines into a single, easy to read, gauge information indicating the current vehicle operating state and the ability to increase power assist. This involves a display of instantaneous rate of consumption usage superimposed over the available rate of power consumption limits. The present invention can display whether an operator is requesting power assist, regenerative braking or battery charging while also showing the amount of power assist, regenerative braking or battery charging that is possible for the vehicle under present operating conditions. Through the use of a vehicle system controller (VSC) or similar type controller connected to the display of the present invention, the instantaneous rate of consumption usage or charge can be limited to the available rate of power consumption or charge limits.

Abstract: The invention is an improved method and system to monitor vehicle operation state and operator requests. It combines into a single gauge information indicating current vehicle operating state and ability to increase power assist using a display of instantaneous rate of consumption usage superimposed over available rate of power consumption limits. The invention can display whether an operator is requesting power assist, regenerative braking or battery charging while also displaying the available amount of each under present operating conditions. A vehicle system controller (VSC) or similar type controller is connected to the gauge, which can limit instantaneous rate of consumption usage or charge to the available rate of power consumption or charge limits. The invention can use analog needles or LEDs in various configurations as well as adding warning lamps or chimes when the instantaneous rate of consumption usage approaches or exceeds the available rate of power consumption limits.

Abstract: An electric or hybrid electric vehicle 7 is provided which includes a first wheeled axle 10 that is electrically driven and has only electric regenerative brakes. The vehicle 7 also includes a second wheeled axle (22, 32, 44) that has only friction brakes 26. The cost and complexity of friction brakes on the second axle (22, 32, 44) can be avoided.

Abstract: A system or method for compensating for low vacuum levels in a brake-by-wire system includes continually monitoring the level of vacuum in a vacuum booster. The state or condition of the vacuum source is also monitored to determine whether it is on or off. When the vacuum source is off, the level of vacuum is measured to determine whether it is at or below a critical level. If the level of vacuum is critically low, the vacuum source is turned on. If the vacuum level is not critically low, the hydraulic boost gain is modified in order to provide more braking pressure in response to brake force exerted at the brake pedal.

Abstract: A torque control strategy control for management of regenerative braking in a motor vehicle. A first processor (12) processes throttle request data (20) and torque modification data (40) from a second processor (14) to develop motor torque request data (28) for controlling rotary electric machine torque. The second processor processes brake request data (26), the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data (30) for controlling friction brake torque applied to the vehicle and the torque modification data for the first processor.

Abstract: An electric powered brake system (10) for braking road-engaging wheels of a motor vehicle. An ignition switch for turning a motor of the vehicle on and off also controls the application of electric power to the electric powered brake system. A control and method (FIGS. 2 and 3) for maintaining application of full electric power to the electric powered brake system when the ignition switch is operated from ON to OFF so long as at least one parameter (60, 62, 64, 66) related to a respective component of the vehicle and indicative of a need to maintain full electric power application to the brake system continues to exist and for discontinuing application of full electric power to the brake system when all of selected ones of several such parameters are indicative of lack of need to maintain full electric power application to the brake system.

Abstract: Requested brake torque and requested throttle torque are assigned opposite algebraic signs in both rollback and non-rollback states. In the non-rollback state, requested motor torque development includes a process step (206) in which requested brake torque and requested throttle torque are algebraically summed. In the rollback state, requested motor torque development includes a process step (218) in which requested throttle torque is substituted for the regeneration torque limit. In the rollback state, the difference between the requested throttle torque and the requested brake torque is compared with a zero vehicle speed regeneration torque limit (228) when the result of comparing the difference between requested throttle torque and the requested brake torque with the regeneration torque limit (222) discloses that the latter difference does not exceed the regeneration torque limit. The result is used to determine respective amounts of motor torque and friction brake torque (230, 232, 234, 236).

Abstract: A vehicle brake system 10 has a brake pedal assembly 14, a sensor 18 or 22 for sensing effort applied to the brake pedal assembly and a brake actuator 26 for generating braking force to be applied to one or more brakes 12A-12D on the vehicle. The brake system further includes a position sensor for sensing a position signal, such as an adjustable brake pedal position sensor 40, a seat position sensor 42, a steering wheel position sensor 44, or a driver position sensor 46, which is generally indicative of the stature and/or comfort of the driver. The brake system further includes a controller 24 for automatically controlling the amount of braking force applied to the one or more brakes in the vehicle as a function of the sensed position. Accordingly, the brake system automatically adjusts the braking effort based on a sensed position signal.

Abstract: An apparatus for reducing motor noise in a motor driven system (12) has a sensor (22) coupled to the system that generates an electrical signal indicative of a system operating parameter. A controller (24) is coupled to the motor (14) and the sensor (22). The controller (24) drives the motor (14) with a pulse width modulated signal having a variable duty cycle. The controller (24) monitors the electrical signal and varies the pulse width modulated signal from a low duty cycle corresponding to a low noise operation of the motor (14) to a higher duty cycle in response to an increased demand as indicated by the sensor.

Abstract: A torque control strategy control for management of regenerative braking in a motor vehicle. A first processor (12) processes throttle request data (20) and torque modification data (40) from a second processor (14) to develop motor torque request data (28) for controlling rotary electric machine torque. The second processor processes brake request data (26), the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data (30) for controlling friction brake torque applied to the vehicle and the torque modification data for the first processor.

Abstract: A master cylinder (12) and pedal feel emulator (10) useful in a brake-by-wire system. A bore (18) of the master cylinder contains three pistons (22, 34, and 28), in tandem, that divide the bore into various zones (26, 24, 32, 30). The emulator contains a piston (74) that divides a bore (72) into two zones (76, 78), and a spring (80) disposed in one of those zones. The zones of the emulator are hydraulically communicated in certain ways with zones of the master cylinder to enable the emulator to be effective during brake-by-wire controlled braking to displace the emulator piston to compress the emulator spring, thereby emulating pedal feel that occurs during hydraulic braking.

Abstract: A system and method for reducing speed of a vehicle to maintain a target vehicle speed include determining an actual vehicle speed, comparing the target vehicle speed to the actual vehicle speed to generate a speed error, determining a continuously variable braking torque as a function of the speed error when the actual vehicle speed exceeds the target vehicle speed, and applying the continuously variable braking torque to at least one wheel of the vehicle to reduce the speed error toward zero and control the speed of the vehicle. The present invention is applicable to vehicles powered by an internal combustion engine, electric vehicles, fuel cell vehicles, and hybrid vehicles. The continuously variable braking torque may be applied using regenerative braking to improve fuel efficiency. Friction brakes may also be utilized either alone, or in combination with regenerative braking, for vehicles capable of brake-by-wire control strategies.

Abstract: A tire monitoring and warning assembly 10 which monitors and measures attributes or characteristics of at least one of the selectively inflatable tires 14-20 of a vehicle 12 and which compares the obtained measurements with a stored value which represents a value of the attribute or characteristic occurring or existing when the at least one tire 14-20 is desirably inflated, and which, based upon the comparison, warns the driver if the at least one of the tires 14-20 is deflated.