A device and a method for controlling vehicle speed in a vehicle equipped with brake cruise control when the vehicle is travelling downhill are provided. The method involves driving a vehicle downhill with the brake set speed set to a first brake set speed; detecting a current vehicle speed; automatically applying a brake torque using at least an auxiliary brake to maintain the first brake set speed; and detecting a manual application of a vehicle service brake, in order to decrease vehicle speed. If a control unit detects that the driver is applying the service brake, then the control unit is automatically arranged to set the brake set speed to a second brake set speed that is lower than the first brake set speed; and to apply a brake torque using at least the auxiliary brake if a detected current vehicle speed exceeds the second brake set speed.

A cruise control arrangement is provided with a cruise control speed function and where the cruise control arrangement is provided with a set cruise speed value and a set brake cruise speed value, and where the cruise control brake function is active when the vehicle travels downhill, where the cruise control arrangement is adapted to activate at least one auxiliary brake when the vehicle speed reaches the set brake cruise speed, to apply a service brake of the vehicle in order to reduce the speed of the vehicle to a predefined first speed if the vehicle speed exceeds the set brake cruise speed when the least one auxiliary brake is delivering full brake power, where the predefined first speed is lower than the set brake cruise speed. Undesired acceleration during downhill travel can be avoided when the brake power of the auxiliary brake is not sufficient. Further, a required downshift can be delayed, which will improve the fuel consumption of the vehicle.

Disclosed herein are a brake actuator and an electromechanical brake using the brake actuator and a control method thereof. The brake actuator provided in a disc brake to press or release a piston and controlled by an electrical signal includes a first actuator including a first power transmission unit configured to transmit power to the piston side; and a second actuator including a second power transmission unit configured to transmit power to the piston side; wherein the first and second power transmission units are arranged coaxially.

A transportation vehicle provides a brake autohold function to maintain braking without requiring the driver to continuously apply pressure on a brake pedal. The vehicle comprises an autohold selector, a parking brake selector, a brake pedal, and an accelerator pedal. A braking system is adapted to enter an autohold event according to a pressed brake pedal at vehicle standstill during an active autohold mode toggled by the autohold selector. A controller is configured to terminate the autohold event in response to either a deactivation command using the parking brake selector or accelerator pedal movement, without deactivating the autohold mode. By manually terminating the brake autohold event the vehicle can begin to creep forward using only the torque generated by the engine at idle, thereby avoiding the additional torque that is generated when the accelerator pedal is used to terminate the brake autohold event.

A hill descent system for a vehicle and a control method thereof comprising: wheels; wheel speed sensors used for detecting the speeds of the wheels; motors used for selectively driving or braking the wheels; a motor controllers, for controlling the working states of the motors; resolver sensors for detecting the rotational speeds of the motors; and a vehicle control unit for determining the actual downhill speed of the vehicle and adjusting the working states of the motors to control the descent of the vehicle.

Methods and apparatus are disclosed herein that perform automatic downhill snub braking. An example apparatus disclosed herein includes an electronic powertrain controller to cause a deceleration of a vehicle in response to a first request from an electronic cruise controller, the first request responsive to a change in grade of a driving surface and an electronic brake controller to apply snub braking to the vehicle in response to a second request received from the electronic cruise controller, the second request responsive to a speed of the vehicle reaching a maximum speed.

A parking assist device includes an electronic control unit. The electronic control unit is configured to: perform parking assist of a vehicle to automatically park the vehicle at a target position while restricting a vehicle speed to an upper limit or lower in accordance with an instruction of a user who is outside the vehicle; determine whether or not the vehicle moves on a road surface having a downhill grade along a travelling direction of the vehicle by the parking assist; and set the upper limit in the case where the vehicle is determined to move on the road surface having a downhill grade to be smaller than the upper limit in the case where the vehicle is not determined to move on the road surface having a downhill grade.

A method for controlling a separating clutch in a power train of a vehicle having a drive motor and a retarder. The clutch is arranged such that a rotor of the retarder is switched into a drive connection with the motor and/or power train via the clutch and a working chamber of the retarder can be filled with an operating medium to build up a braking power such that braking torque is exerted by the retarder onto the power train and/or motor. A control system switches the clutch into a closed or an open position. The switching of the clutch into the closed position occurs depending on an input signal to the controller, and the clutch is switched back into the open position depending on essentially no medium being present in the working chamber of the retarder and that predetermined limits of an operating and/or environmental parameter are not exceeded.

A method for operating a speed control system of a vehicle is provided. The method comprises detecting an occurrence of a slip event, of a step encounter event, or of both events at a leading wheel of the vehicle. The method also comprises predicting that the occurrence of the detected event(s) will occur at a following wheel of the vehicle. The method yet further comprises automatically controlling vehicle speed, vehicle acceleration, or both vehicle speed and acceleration in response to the detection, the prediction, or both the detection and prediction. A speed control system comprising an electronic control unit (ECU) configured to perform the above-described methodology is also provided.

The present invention relates to a method for controlling a vehicle in association with a descent, the vehicle having a powertrain comprising: a drive unit configured to provide propulsion power; an auxiliary brake device; and a first cooling circuit comprising a first coolant; wherein the drive unit and the auxiliary brake device are arranged to be selectively connected or disconnected with/from the first cooling circuit, wherein the drive unit has a first maximum temperature and the auxiliary brake device has a second maximum temperature higher than the first maximum temperature, the method comprising: controlling the drive unit to reduce the provided propulsion power when the vehicle is approaching an upcoming descent, which fulfils predetermined criteria; disconnecting the drive unit from the first cooling circuit; connecting the auxiliary brake device with the first cooling circuit; and controlling the auxiliary brake device to brake to vehicle down the descent.