Daimler Chrysler Ag

Mercedes-benz Aktiengesellschaft

Other

Daimler-benz Ag

Michael Reiner

Bernhard Toepfer

Wolfgang E Mueller

Rudolf Maurath

Ali Aminpour

Bodo Klein

Reinhard Helldoerfer

Joerg Fischer

Imre Boros

Joachim Pressel

Dieter Hamann

A method controls a vehicle brake system having a service brake and a retarder in a mutually coordinated manner. The retarder is activated during each braking operation and is controlled as a function of the driver's braking desire as well as of driving condition values, road condition values and operating conditions of the vehicle (integrated operation of the retarder).

Service brake and retarder method for controlling the brake system of a vehicle in a mutually coordinated manner

A method controls brake pressure for a motor vehicle pressure medium-actuated power brake system in which the adjustment of a proportionality factor (k) between deceleration and brake pressure starting from an initial value (k ) is limited to a range bounded by a lower limit value and an upper limit value in which range the initial value (k ) is contained. This produces a warning travel of the pedal when excessive deviation of the brake pressure from the expected value occurs. The warning travel informs the driver of the braking effect which is deviating excessively from the expected degree. Methods are known in which a specific travel (s ) of the brake pedal is interpreted as a setting of a specific desired deceleration (z ) of the vehicle and the required brake pressure is set automatically if appropriate by incrementally adjusting a variable proportionality factor (k).

Brake pressure control method for a motor vehicle power brake system

A method for producing a deceleration setpoint value of a motor vehicle with an electropneumatic brake actuatable by a brake pedal, especially a compressed-air-actuated brake, with a sustained action brake and with at least one device for actuating the brake independently of the driver's desire (external actuation) is characterized by the fact that, with external actuation of the brake and with a simultaneous change in the brake pedal, a resultant deceleration setpoint (z_res) is formed in such fashion that, beginning with the externally set deceleration setpoint (z_ext) with simultaneous actuation of the brake pedal, a curve of the resultant deceleration setpoint (z_res) with the pedal travel is produced which reaches complete deceleration upon full brake pedal travel.

Method for forming a deceleration setpoint on a motor vehicle

For regulating the driving dynamics of a road vehicle, setpoints for the yaw rate {dot over (&PSgr;)} and the float angle &bgr; of the vehicle are generated continuously by evaluating a simulation computer implemented vehicle model. The simulation computer generates control signals for activating at least one wheel brake of the vehicle based on a comparison of the reference values {dot over (&PSgr;)},as a setpoint, and the actual values {dot over (&PSgr;)},of the yaw rate continuously recorded by a yaw rate sensor. The vehicle model is represented by a linear differential equation system of the form &lsqb;P&rsqb;&middot;({overscore ({dot over (X)})})&equals;&lsqb;Q&rsqb;&middot;({overscore (X)})&plus;({overscore (C)})&middot;&dgr;(t). The driving-dynamic state values &bgr;,(k&minus;1) and {dot over (&PSgr;)},(k&minus;1) are updated at a point in time t(k&minus;1), followed by a point in time t(k) that is later by a clock time interval T,, by evaluation of the system of equations

Process for controlling driving dynamics of a street vehicle

The gradient of a roadway in the direction of travel of the vehicle is identified from signals present in the vehicle without any additional sensor systems. A freely rolling state of the at least one driven axle of the vehicle is detected at least once. In this state, the wheels of the driven axle also roll free of slip. In order to balance out the wheel speeds between the driven axles and the non-driven axles, the difference speed between the wheel speed of a driven axle and the wheel speed of a non-driven axle is identified. At the same time, the value of the braking, that is to say the value of the deceleration of the vehicle, is measured. The value of a gradient constant is identified from the identified values of the difference speeds and the braking operations. The gradient of the roadway can be determined with the gradient constant from the values of the difference speed and the values of the braking then identified. The gradient information can then be used to control the vehicle.

Method for determining the gradient of a roadway

A method sets the braking effect of the retarder brake as a function of the absolute value of the difference between wheel speed values which are derived from wheel speeds at wheels which can be influenced by the retarder brake and from wheel speeds at wheels which cannot be influenced by the retarder brake. The braking effect is reduced if the absolute value of the difference exceeds a prescribed limit value which is lower than the absolute value of the difference when one of the wheels starts to tend to lock. The effect of the retarder brake can thus already be reduced significantly before the locking point is reached so that the risk of wheels locking which otherwise exists owing to the comparatively slow decrease in braking torque of retarder brakes and thus the associated swerving of the axle of the retarder brake are reliably avoided.

Motor vehicle retarder brake control method

A method of wear-dependent braking force distribution prevents adhesion problems without being limited to lowest brake pressures as is the case with conventional methods. Wear control is dispensed with only in the case of operationally very rare braking actions, for example, those above 0.3 g or a learned adhesion threshold. These rare braking actions are limited, in practice, to genuinely critical braking situations. Otherwise, the control interventions are carried out with to produce balanced wear only in the long term; an attempt is made to achieve wear at the same rate rather than simply balanced wear.

Method of determining a wear-dependent braking force distribution

A process for load dependent braking regulations (ALB) utilizing components, signal paths and transmitters of an existing anti-lock braking system (ABS) to perform an automatically load-dependent braking function which takes effect well below the locking limit. The brake pressure and consequently the brake distribution are controlled by processing only wheel-speed differences as actual values of an electronic brake-pressure controller instead of absolute wheel slips. To compensate for changing load situations and roadway properties, the precontrollable brake-force distribution and the brake-pressure level control triggerable at the pedal are corrected in a self-learning and adaptive manner. The device for carrying out the ALB process consists essentially of a computer and software program using input from the ABS systems. The process according to the invention makes axle-load sensors superfluous.

Growing community of inventors

Fellbach, Germany

Michael Reiner