Abstract: The present invention relates to an electrically operable brake system and a method for its actuation. The brake system and the method are characterized in that the service brake system can be activated by two brake operating devices which are operable by the driver independently of each other. The main advantage which results is that upon failure of a brake operating device which is e.g. configured as a brake pedal module, braking of the vehicle can be achieved by means of the service brake system by way of the second brake operating device. The additional functions intended for the service brake system, such as ABS, TCS, driving dynamics control, brake assist system, etc., may then be implemented, if so desired. The redundant design of the actuation for the service brake permits achieving a high degree of operational safety because full braking functions can be maintained even in case of emergency braking.

Abstract: A method and system for controlling a brake for motor vehicles. The present invention relates to a method as well as a system for controlling a brake for motor vehicles, which can be electromechanically actuated by means of an actuator, consisting of an electric motor as well as a drive mechanism positioned downstream of the electric motor. In order to be able to increase motor speed under certain operating conditions, i.e. according to demand, without reducing the available torque, the invention provides for the slope of the speed-torque characteristic curve of the electric motor (4) to be modified by weakening components of the electromagnetic field of said electric motor (4), which affect the dynamics of same, in such a way that a higher speed (&ohgr;′1) is obtained at the same torque (M1).

Abstract: The present invention discloses an actuating unit for use on an electromechanically actuated disc brake for automotive vehicles which is basically composed of a drive unit (1) or an electric motor (11), an actuating element (7) by means of which one (4) of two friction linings (4, 5) displaceably arranged in a brake caliper is moved into engagement with a brake disc (6), and a first and a second reducing gear (2, 3). The first reducing gear (2) is provided as a ball screw (16-18), while a planetary gear (30-34) is used as the second reducing gear (16-18).

Abstract: The present invention discloses an actuating unit for an electromechanically operable disc brake for automotive vehicles which is generally comprised of a drive unit or an electric motor, an actuating element, by means of which one of two friction linings that are slidably arranged in a brake caliper is moved into engagement with a brake disc, as well as a first and a second reduction gear. In order to uncouple the second reduction gear from the first reduction gear, it is disclosed in the present invention that the electric motor, the first reduction gear, and the second reduction gear are configured as at least two assemblies which can be handled independently.

Abstract: This invention relates to an electromechanical brake system, in particular for automotive vehicles, which includes a pedal module and at least two brake modules. Further, a central module may be provided. Connection between the aforementioned modules can be made by a data bus. The data bus is provided redundantly. In one embodiment, the central module can evaluate signals of a sensor system and examine them for their errors. Further, the central module can emit a corresponding nominal braking value which then is emitted to the brake modules. Thereupon, the brake modules determine appropriate actuating signals for the actuators which interact with the wheels in order to realize the driver's braking intention.

Abstract: Electronic brake systems are functionally split-up safety-critical real-time systems which are subject to high standards with regard to error detection and error handling. This invention describes a method and corresponding device for error handling in such systems which permits only a few defined system conditions, inclusive of a pre-check, with the transition from one system condition to the next condition only being possible if certain defined events take place.

Abstract: An electromechanical brake system, particularly for motor vehicles, with a pedal simulator and brake modules is disclosed. A central module is also provided. The connection between the aforesaid modules can be provided by a data bus. The central module evaluates the braking request signals from a sensor device and checks them for errors. Also, a central module supplies and appropriate desired braking value based on the braking request and possibly higher functions such as ABS or ASR. The desired braking value is then conveyed on to the brake module, which then determines the corresponding control signals for the actuators, which interact with the wheels in order to brake the vehicle as the driver requires.

Abstract: In traffic-related stationary phases, a drive ratio of the transmission remains engaged with the engine running on a road vehicle equipped with automatic transmission. The service brake automatically remains activated for a short time after the vehicle has come to a halt as a result of a targeted braking operation. Thereby, the driver is allowed to remove his/her foot from the brake pedal, and the vehicle can be held stationary in a reliable manner on a flat or sloping road surface. This holding braking mode of the vehicle service brake system is cancelled when the driver actuates the accelerator pedal whose position is monitored by a switch.

Abstract: A brake-pressure control device is provided for a road vehicle with electrohydraulic multi-circuit brake system. For each wheel brake, a hydraulic servo-cylinder is driven by an electric motor. The servo-cylinders enables certain functions to be implemented, namely spot braking mode, including electronic control of the VA/HA braking force distribution (EBKV); anti-lock braking control (ABS function); traction control (TCS function); and vehicle movement control as a result of automatically controlled increase in brake slip at one or more of the wheels of the vehicle. A desired-value setting unit with a single-circuit master cylinder is provided which, in normal electronically controlled braking mode, serves as a desired-value transmitter and, in the event of failure of the vehicle's electronic system, can be activated as an emergency braking unit for building up brake pressure in the front-wheel brakes.

Abstract: A brake-pressure control device for a hydraulic multi-circuit brake system provides for brake-pressure generation, in addition to a brake unit, hydraulic regulating cylinders with electromotively drivable pistons. By electronic activation of the cylinders, the wheel brakes can be activated even without the cooperation of the driver. In the regulating cylinders of the front-wheel brakes, the pistons have a basic position, out of which brake-pressure build-up and reduction strokes can be executed. The pistons of the regulating cylinders of the rear-wheel brakes have a basic position which corresponds to the largest volume of the outlet-pressure spaces. The regulating cylinders are equipped with electronic position transmitters. A sensor whose output signal measures the expected value of the vehicle deceleration with which the driver wishes to brake is also provided.

Abstract: A method is provided for determining the start and the end of an automatic braking process to optimize the triggering of the automatic braking process. When a set value is exceeded, an automatic braking process is triggered. The threshold value is changed as a function of the driving state, in particular, as a function of the speed of the vehicle when the brake pedal is actuated, and independently thereof, as a function of the position of the brake pedal. In addition, various criteria terminate the automatic braking process as a function of the actuation force of the brake pedal, of the speed of the vehicle and of the pedal travel.

Abstract: A device monitors an automatic braking process by using a fault-detecting, operational testing method which takes place via an automatic braking process lasting only briefly, typically about 50 ms. The method is initiated by a test control device and can take place during different vehicle states.

Abstract: A method for terminating an automatic braking process improves an automatic braking process by assuring that reliable termination of the braking process always takes place. Breaking-off criteria, which are independent of the actuation force of the brake pedal, are provided for the automatic braking process. The variables relating to the dynamics of vehicle movement or the activation time of the automatic braking process, if appropriate also as a function of variables relating to dynamics of vehicle movement, are used as the breaking-off criteria. Thus, automatic braking process is terminated as a function of vehicle behavior. In addition, the gradient of the braking pressure is determined as a function of the activation time and/or as a function of the switch-off criteria when the automatic braking process is terminated.

Abstract: A brake pressure control device for a road vehicle with a hydraulic brake system has a pneumatic braking force amplifier which is provided with a switch-over device which switches ever the braking force amplifier to operation with increased amplification factor when the speed with which the driver actuates the brake pedal exceeds a threshold value .phi..sub.s. In the axial force transmission train leading from the brake pedal via a reaction piston of the control part, via a reaction element and via the actuating piston of the braking force amplifier to the main cylinder. A rigid force transmission element is in mechanical parallel connection to a flexible transmission element and associated with which there is a position engaged in the force transmission train as the basic position for the judicious braking operation, and an actuation device, which responds when the threshold value .phi..sub.s of the pedal actuation speed is exceeded and then disengages the distance piece from its supporting position.

Abstract: In a brake-pressure control device for a road vehicle, having an antilock braking system whose braking device comprises a vacuum brake power assist unit which has a vacuum chamber connected to the intake stub of the vehicle engine and a working chamber which can be subjected to a higher pressure via a control element operable by the brake pedal, a position sensor is provided which detects the position of the brake pedal and generates output signals. An electronic control unit processes these signals and generates drive signals for a brake-pressure control device making it possible to couple into the wheel brakes a higher brake pressure than would otherwise correspond to the instantaneous pedal position. Such driving of the brake-pressure control device is triggered when the speed .PHI. at which the brake pedal is operated overshoots a prescribed threshold value .PHI..sub.s.

Abstract: A brake-pressure control device for a road vehicle with a hydraulic brake system has a pneumatic brake booster provided with a change-over device which changes over the brake booster to a mode with an increased boost factor when the speed with which the driver actuates the brake pedal exceeds a threshold value. A reaction piston of the axial force-transmission train, leading from the brake pedal via the reaction piston, a flexible reaction element and the driving piston of the brake booster to the master cylinder, is constructed in two parts. One of the two part-pistons engages axially on the reaction element and the other of the part-pistons acts as a valve element of the inlet valve and via which the driving chamber of the brake booster can be exposed to the ambient pressure. The two part-pistons have complementary threads which engage one another.