An electronic bicycle includes a torque control system that controls what torque is applied to wheels of the electronic bicycle by electronic hub motors. The torque control system may determine a torque to apply to the wheels based on user input signals. The torque control system also may detect when the wheels of the electronic bicycle are slipping, and adjust the torque to minimize the time that the wheel is slipping. Additionally, the torque control system may determine a coefficient of friction between the wheels and the ground and determine a maximum torque to apply to the wheels based on the coefficient of friction. Furthermore, when braking, the torque control system may determine whether torque is applied to the wheels by passive braking or by active braking.

Disclosed is a method for actuating a parking brake system in a utility vehicle. In an example, the parking brake system includes an operational actuator for actuating a parking brake and a control unit for controlling the operational actuator. When the utility vehicle is stopped, a stored brake-application characteristic is selected for the parking brake as a function of a current vehicle condition of the utility vehicle. Based on the selected application characteristic, the operational actuator is activated by the control unit in order to apply the parking brake. In addition, or alternately, when the utility vehicle is started, a stored brake-release characteristic is selected for the parking brake as a function of a current vehicle condition of the utility vehicle. Based on the selected brake-release characteristic, the operational actuator is activated by the control unit in order to release the parking brake.

An electronic bicycle includes a torque control system that controls what torque is applied to wheels of the electronic bicycle by electronic hub motors. The torque control system may determine a torque to apply to the wheels based on user input signals. The torque control system also may detect when the wheels of the electronic bicycle are slipping, and adjust the torque to minimize the time that the wheel is slipping. Additionally, the torque control system may determine a coefficient of friction between the wheels and the ground and determine a maximum torque to apply to the wheels based on the coefficient of friction. Furthermore, when braking, the torque control system may determine whether torque is applied to the wheels by passive braking or by active braking.

Systems and methods for operating an electric power distribution bus of an electric or hybrid vehicle are described. In one example, an output of an electric power consumer is decoupled from other electric power consumers so that electric current drawn from the electric power distribution bus is lowered while the electric power consumer provides a capacitive load to the electric power distribution bus, thereby reducing voltage ripple associated with the electric power distribution bus.

A cooling system and method for an auxiliary braking device of a hydrogen fuel cell truck, are provided in consideration that auxiliary braking force generated by the regenerative braking of the motor may be unnecessary and the brake resistor may be unnecessary when a sufficient amount of auxiliary braking force is generated alone by the operation of a retarder. A portion of thermal energy generated by the retarder is distributed to a stack cooling system so that the portion of thermal energy is removed by the stack cooling system. Accordingly, due to sufficient cooling of the retarder, a sufficient amount of auxiliary braking force is provided, and the brake resistor that has consumed surplus electrical energy generated by regenerative braking is removed.

A cooling system and method for an auxiliary braking device of a hydrogen fuel cell truck, are provided in consideration that auxiliary braking force generated by the regenerative braking of the motor may be unnecessary and the brake resistor may be unnecessary when a sufficient amount of auxiliary braking force is generated alone by the operation of a retarder. A portion of thermal energy generated by the retarder is distributed to a stack cooling system so that the portion of thermal energy is removed by the stack cooling system. Accordingly, due to sufficient cooling of the retarder, a sufficient amount of auxiliary braking force is provided, and the brake resistor that has consumed surplus electrical energy generated by regenerative braking is removed.

A vehicle includes a powertrain having an electric machine configured to power driven wheels, an accelerator pedal, and a brake pedal. A controller is programmed to, in response to driver-demanded torque corresponding to a position of the accelerator pedal, selectively brake the vehicle via operation of the electric machine, in further response to a speed of the vehicle being greater than a threshold, limit a rate of change of the driver-demanded torque commanded to the powertrain based on a first rate limit, and, in further response to the speed being less than another threshold, limit a rate of change of the driver-demanded torque commanded to the powertrain based on a second rate limit that is higher than the first rate limit such that, for a given driver-demanded torque, acceleration and deceleration of the vehicle is more responsive than when the first rate limit is applied.

Wheel brakes of one vehicle axle of a dual-circuit hydraulic-power vehicle brake system for an electric or hybrid vehicle are connected to one brake circuit. Brake pressure is applied by a power brake-pressure generator to the two brake circuits with a time offset. It is thereby possible to compensate for a deceleration effect of an electric motor of the vehicle, which is operated as a generator during a braking.

Wheel brakes of one vehicle axle of a dual-circuit hydraulic-power vehicle brake system for an electric or hybrid vehicle are connected to one brake circuit. Brake pressure is applied by a power brake-pressure generator to the two brake circuits with a time offset. It is thereby possible to compensate for a deceleration effect of an electric motor of the vehicle, which is operated as a generator during a braking.

A controller, responsive to accelerator pedal release and a speed of the vehicle being less than a threshold, operates an electric machine to provide braking torque according to a predetermined speed versus time profile that defines a predetermined duration for the speed to become zero and a target speed for each time instant during the predetermined duration such that, for a given one of the time instants, the electric machine increases the braking torque responsive to the speed being greater than the target speed and decreases the braking torque responsive to the speed being less than the target speed.