An apparatus determines a road friction of a commercial vehicle. The commercial vehicle has a first axle and a second axle, a load distribution mechanism for changing a load on the first axle or on the second axle, and a slip sensor for determining a slip value for at least one wheel on the first axle or on the second axle. The apparatus includes an evaluation unit configured to control the load distribution mechanism to change the load of the first axle or on second axle, determine a change in the slip value in response to the change of the load, and evaluate the road friction based on the change in the slip value.

A vehicle arrangement for braking comprising at least a first electric motor comprising a first shaft being arranged to be mechanically connected to a drive shaft of the vehicle via a gearbox, and a braking compressor comprising a compressor shaft being arranged to be mechanically connected to the first shaft of the first electric motor via a compressor clutch, such that the first shaft drives the compressor shaft, wherein the first shaft is connected to the gearbox via a first motor clutch and a first gearbox shaft, the arrangement further comprising a mass flow rate controlling means arranged for controlling the air mass flow rate through the compressor. A method for controlling a vehicle arrangement, a method for braking a shaft of an electric motor, a control unit, a vehicle, a computer program and to a computer readable medium.

A method decelerates a vehicle combination of a tractor vehicle and a trailer vehicle that has a trailer braking system. A brake control unit of a tractor vehicle braking system monitors the braking behavior of the tractor vehicle or vehicle combination and adjusts the brake pressure at the wheel brakes of the corresponding wheels of the tractor vehicle and a trailer brake pressure. The brake control unit detects a driver deceleration request to a retarder system and, during activation of the retarder system, monitors whether a predefined safety criterion is met, on the basis of a continually determined braking state variable. After a request to the retarder system by the driver, the stability of the vehicle combination is ensured in that, when the safety criterion is met, a portion of the deceleration request to the retarder system yet to be effectuated is effectuated by the trailer braking system.

Various examples of a controller, method and system for monitoring a tractor-trailer vehicle train are disclosed. In one example a tractor controller is manually-initiated or a user-initiated tractor controller and includes an electrical control port for receiving an electrical sync signal and an electrical start signal, and a communications port for receiving data. A processing unit of the tractor controller includes control logic and is in communication with the electrical control port. The control logic is capable of receiving a data signal at the communications port which includes a time value and a unique identification which corresponds to the towed vehicle in response to the electrical start signal. At a predetermined response time, the tractor controller determines the position of the towed vehicle in the tractor-trailer vehicle train based on the data received from the towed vehicles.

The invention relates to a method of controlling a heavy-duty vehicle in a slope when the vehicle has come to a standstill due to service brakes of the vehicle having applied a service brake force, the method comprising determining a total brake force required for maintaining the vehicle at standstill, activating at least one park brake for providing a park brake force, gradually increasing the park brake force, and, while the park brake force is gradually increased, gradually reducing the service brake force while maintaining the sum of the service brake force and the park brake force at least equal to the determined total brake force.

Towed vehicles can be extremely heavy. Accordingly, it is too much of a burden to the braking system of a towing vehicle to not have brakes on the towed vehicle. Controlling the brakes of the towed vehicle must be accurately applied otherwise undesirable conditions can be created. There is a need for a method for controlling braking of a towed vehicle. This method comprises receiving a first signal via a communication bus of a towing vehicle, the first signal relating to at least one operating condition of at least one the towing vehicle and a towed vehicle, sending a second signal to brakes of the towed vehicle, the second signal based on said first signal.

A method for decelerating a vehicle combination including a towing vehicle having a towing vehicle brake system and at least one trailer vehicle having a trailer brake system with an anti-lock brake system includes applying, by the towing vehicle brake system, a brake pressure to pneumatically operable wheel brakes of the towing vehicle according to a desired deceleration specified by a driver, and providing, by the towing vehicle brake system, a trailer brake pressure for the trailer brake system of the at least one trailer vehicle. An electronic brake control unit of the towing vehicle brake system: detects a current actual vehicle deceleration value continuously compares the current actual vehicle deceleration actual value with a maximum deceleration, and, when the current actual vehicle deceleration value reaches or exceeds the maximum deceleration, limits the brake pressure and provides an information signal.

Towed vehicles can be extremely heavy. Accordingly, it is too much of a burden to the braking system of a towing vehicle to not have brakes on the towed vehicle. Controlling the brakes of the towed vehicle must be accurately applied otherwise very dangerous conditions can be created. A method of controlling braking of a towed vehicle is, therefore, needed. The method comprises receiving speed signals based on speed of a towing vehicle, or a towed vehicle, or both said towing vehicle and said towed vehicle, receiving pressure signals based on pressure of a hydraulic brake system of the towing vehicle, and generating a brake output signal based on the speed signals and the pressure signals.

Towed vehicles can be extremely heavy. Accordingly, it is too much of a burden to the braking system of a towing vehicle to not have brakes on the towed vehicle. Controlling the brakes of the towed vehicle must be accurately applied otherwise undesirable conditions can be created. There is a need for a method for controlling braking of a towed vehicle. This method comprises receiving a first signal via a communication bus of a towing vehicle, the first signal relating to at least one operating condition of at least one the towing vehicle and a towed vehicle, sending a second signal to brakes of the towed vehicle, the second signal based on said first signal.

A method for decelerating a vehicle combination including a towing vehicle having a towing vehicle brake system and at least one trailer vehicle having a trailer brake system with an anti-lock brake system includes applying, by the towing vehicle brake system, a brake pressure to pneumatically operable wheel brakes of the towing vehicle according to a desired deceleration specified by a driver, and providing, by the towing vehicle brake system, a trailer brake pressure for the trailer brake system of the at least one trailer vehicle. An electronic brake control unit of the towing vehicle brake system: detects a current actual vehicle deceleration value continuously compares the current actual vehicle deceleration actual value with a maximum deceleration, and, when the current actual vehicle deceleration value reaches or exceeds the maximum deceleration, limits the brake pressure and provides an information signal.