This travel control device includes: a road determining unit which determines whether a road including a downward slope along which a vehicle is traveling includes a first curved road and a second curved road; and a travel control unit which, if the road determining unit has determined that the road contains the first curved road and the second curved road, causes the vehicle, when being caused to travel in such a way as to maintain a target speed, to decelerate at a curved road entry side of the first curved road and to coast from a curved road exit side of the first curved road, such that the vehicle can pass through the first curved road.

A vehicle computer system controls downhill speed of a vehicle having a cruise control and an engine retarder. The system receives a request to increase engine retarder demand. In response, the system increases an engine retarder demand setting and, if cruise control is active, decreases a downhill speed control (DSC) cruise control offset. The engine retarder system may automatically activate to reduce the vehicle speed to a cruise control set speed plus the DSC cruise control offset. In an embodiment, the request to increase engine retarder demand is generated in response to operator input via an engine retarder demand input device (e.g., a steering-column-mounted control stalk). The system may also receive a request to decrease engine retarder demand in the engine retarder of the vehicle. In response, the system decreases the engine retarder demand setting and, if cruise control is active, increases the DSC cruise control offset.

A method for learning braking step threshold values of a sustained-action brake includes detecting a braking requirement setpoint, controlling the sustained-action brake with the braking requirement setpoint to generate a braking effect variable of the sustained-action brake, and detecting a sustained-action brake actual braking effect variable and a maximum sustained-action brake braking effect. The method additionally includes forming a braking effect variable coefficient that characterizes a ratio of the sustained-action brake actual braking effect variable and the maximum sustained-action brake braking effect variable that results from control of the sustained-action brake with the braking requirement setpoint, and assigning the braking effect variable coefficient to a braking step of the sustained-action brake such that each braking step is assigned only one braking effect variable. Additionally, the method includes storing the braking requirement setpoint that results in the braking effect variable coefficient.

A method for learning braking step threshold values of a sustained-action brake includes detecting a braking requirement setpoint, controlling the sustained-action brake with the braking requirement setpoint to generate a braking effect variable of the sustained-action brake, and detecting a sustained-action brake actual braking effect variable and a maximum sustained-action brake braking effect. The method additionally includes forming a braking effect variable coefficient that characterizes a ratio of the sustained-action brake actual braking effect variable and the maximum sustained-action brake braking effect variable that results from control of the sustained-action brake with the braking requirement setpoint, and assigning the braking effect variable coefficient to a braking step of the sustained-action brake such that each braking step is assigned only one braking effect variable. Additionally, the method includes storing the braking requirement setpoint that results in the braking effect variable coefficient.

This invention seeks to replace traditional brakes with a safer and more economical design. The traditional design uses friction to slow a vehicle, while the proposed design uses hydraulic fluid to slow down the motion of a vehicle. The rotor blade, whose design is shown in FIG. 1B, is mounted upon the bearing and is housed with the hydraulic fluid in the housing in FIG. 1A.

A hydrodynamic retarder system for a vehicle is provided. In a first operational state with the vehicle powered on and a retarder deactivated, a pump directs fluid flow from a fluid sump to a retarder inlet valve in the closed position and directs fluid flow to a second sump. In a second operational state with the vehicle on and the retarder activated, the retarder inlet valve moves to the open position directing fluid flow into a retarder chamber and flowing out of the retarder chamber after filling a second volume and discharging to the second sump.

A hydrodynamic retarder system for a vehicle is provided. In a first operational state with the vehicle powered on and a retarder deactivated, a pump directs fluid flow from a fluid sump to a retarder inlet valve in the closed position and directs fluid flow to a second sump. In a second operational state with the vehicle on and the retarder activated, the retarder inlet valve moves to the open position directing fluid flow into a retarder chamber and flowing out of the retarder chamber after filling a second volume and discharging to the second sump.

A vehicle computer system controls downhill speed of a vehicle having a cruise control system and an engine retarder system. The system receives a request to increase engine retarder demand. In response, the system increases an engine retarder demand setting and, if cruise control is active, decreases a downhill speed control (DSC) cruise control offset. The engine retarder system may automatically activate to reduce the vehicle speed to a cruise control set speed plus the DSC cruise control offset. In an embodiment, the request to increase engine retarder demand is generated in response to operator input via an engine retarder demand input device (e.g., a steering-column-mounted control stalk). The system may also receive a request to decrease engine retarder demand in the engine retarder system of the vehicle. In response, the system decreases the engine retarder demand setting and, if cruise control is active, increases the DSC cruise control offset.

A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.

A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.