Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Daimler-benz Ag

Manfred Steiner

Bernd Knoff

Heinz Leiber

Joachim Nell

Siegfried Rump

Wolfgang Kiesewetter

Albrecht Eckl

Alexander Fuchs

Franz Brugger

Lorenz Maack

Martin Klarer

Eberhard Pfeifle

Carsten Lauer

Christoph Steffi

Brian Douglas

Walter Klinkner

Werner Reichelt

Georg Coermann

Walter Klinker

Dieter Ammon

Karl-Eugen Laubacher

Johannes Clauss

Peter Bosch

Manfred F Brugger

Fredy Eckstein

A brake system for a vehicle is equipped with a brake servo assistance unit for the automatic generation of brake force and with at least one sensor for the generation of a measuring signal. This signal represents an activity on the part of the driver and can be fed to a brake pressure control unit. An activation control signal for the actuation of the brake servo assistance unit can be generated should the measuring signal lie within an activation value range. In order to improve operating reliability, at least two sensors are provided for measurement of an activity on the part of the driver, and an activation control signal can be generated should the measuring signals from the sensors each exceed a reference value.

Brake system for a motor vehicle

In a method for carrying out an automatic braking operation in a vehicle, a stte variable for describing driver's reactions and/or events outside the vehicle is sensed by means of a sensor, compared with a reference value and, when the reference value is exceeded, a higher braking pressure than the braking pressure corresponding to the brake pedal position is generated. In order to increase reliability, the automatic generation of braking pressure is suspended for a specific holding time if the state variable which is sensed by sensor means lies outside an acceptable tolerance range.

Method for automatic braking of a vehicle

In a method for controlling the distance and/or the speed of a following vehicle running behind a leading vehicle, the distance between the following vehicle and leading vehicle is measured, and the speeds of the following vehicle and of the leading vehicle are measured, in the event of undershooting a minimum distance and/or in the event of overshooting a minimum speed difference a desired deceleration is determined for the following vehicle and automatic actuation of the vehicle brake on the following vehicle is initiated. The automatic actuation of the vehicle brake is triggered only for the case in which the absolute value of the desired deceleration overshoots a threshold value.

Method and control system for distance and speed control of a vehicle

A method for determining an initiation threshold value for an automatic braking process, in which an automatic braking process is used and a brake pressure is produced which is greater than the brake pressure which corresponds to the operation of the brake pedal by the driver. Short distances between vehicles increase the risk of accidents. If a driver operates the brakes when there is a short distance between the vehicle and the preceding vehicle, in the vast majority of cases, the driver of the following vehicle is often required to perform an emergency braking due to the short distance between the vehicles. To improve the safety of vehicles, an emergency braking is performed, as quickly as possible, when the distance between vehicles is short. This emergency braking, within what is physically possible, ensures rapid deceleration of the vehicle and thus helps to avoid rear-impact accidents. While performing the automatic braking process, the method incorporates a reduction of the initiation threshold value if it is determined that the distance to a preceding vehicle is less than a predetermined limit.

Method for determining an initiation threshold value for an automatic braking process

A process and device are disclosed for preventing a vehicle from colliding with an obstacle during parking. The object of the invention is therefore to ensure that a collision can be reliably avoided without any additional intervention of the drive. In a device with at least one sensor for generating signals which represent the distance between the vehicle and an obstacle, the signals are processed in an evaluation unit. When at least one distance-representing signal falls below a limit value, a warning signal is generated. This warning signal drives a control valve which generates a pressure difference between the working chamber and the vacuum chamber in a brake booster when the warning signal is generated. This pressure difference causes the braking pressure to rise in the wheel brake cylinder and therefore slows the vehicle down to a standstill.

Preventing the collision of a vehicle with an obstacle

An automatic braking operation is triggered before the operation of the brake pedal if, as the required criterion, the operating speed exceeds a triggering threshold value when the gas pedal is released. The triggering threshold value is adapted to the driver's actions to achieve a more reliable separation between necessary and unnecessary triggerings of the automatic braking operation. At least one magnitude is detected which represents the driver's actions and, on the basis of this magnitude, the triggering threshold value for the automatic braking operation is determined. It is thus unimportant whether the required criterion for the triggering of the automatic braking operation is sufficient or whether additional criteria are required for this purpose, such as the determination of a transfer of the driver's foot from the gas pedal to the brake pedal.

Method for determining a triggering threshold value for an automatic braking operation

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.

Road vehicle brake system actuating device and method for holding the

A process carries out an automatic braking operation in which, when the return speed of the accelerator pedal exceeds a threshold value and a transfer of the driver's foot from the accelerator pedal to the brake pedal is determined, an automatic braking operation is triggered. During that operation, a brake pressure is generated in the wheel brakes and is terminated when either a defined time has been exceeded since the triggering of the braking operation or when an operation of the brake pedal takes place by the driver. A support of the driver is ensured when operating the brake pedal in critical driving situations and a brake pressure buildup is carried out even before the operation of the brake pedal by the driver. After the automatic braking operation has been triggered, monitoring occurs to determine whether the time derivation of a quantity representing the operation of the brake pedal exceeds a threshold rise value. In such event, exceeding of the threshold rise value must take place within a defined time period after the triggering of the automatic braking operation, whereby the automatic braking operation is continued.

Process for carrying out an automatic braking operation

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.

Vehicle brake-pressure control device for electrohydraulic multi-circuit

The invention provides a method for determining a threshold value for triggering an automatic brake application wherein a braking pressure greater than that corresponding to the position of the brake pedal is developed when the actuating speed of the brake pedal exceeds a triggering threshold value determined from a preset threshold value and a vehicle-specific correction factor. According to the invention, a standard curve is stored representing the relationship between the vehicle deceleration and the pedal travel, said standard curve having a pedal travel value sP0 for a vehicle deceleration aFZG0=0 m/s.sup.2. During a brake application, pairs of values for pedal travel and vehicle deceleration are determined several times, with a pedal travel value sPi0 being determined for a vehicle deceleration of 0 M/s.sup.2 corresponding to each value pair, based on a curve that is the same as the standard curve. A sliding average sPm is then calculated from the values of sPi0 obtained, and the relative deviation ABW=sPm/sP0 is then determined from the value sP0 as a vehicle-specific correction factor ABW. The triggering threshold value is then determined as a function of the product of the preset threshold value VS and the vehicle-specific correction factor ABW.

Method for determining a triggering threshold value for an automatic

A procedure is provided to end an automatic braking operation such that unwanted ending of the automatic braking operation is prevented. If a switching operation of the switching element takes place within a predetermined time interval after the triggering of the automatic braking operation, the automatic braking operation is not automatically ended. The system monitors whether another switching operation takes place within the time interval. The other switching operation is the reverse of the first switching operation. If another switching operation takes place during the time interval, a second relative motion between the push rod and the component which can be moved within a defined motional play has taken place in this time period. Since the brake pedal is continuing to be actuated, the automatic braking operation is not then ended.

Process for ending an automatic braking operation

In an automatic braking procedure which can be terminated whenever the brake pedal is moved in the direction of its rest position, a braking pressure which is higher than would correspond to the pedal position of the brake pedal is generated where it is established by a triggering criterion that an emergency braking is in force. The invention ensures that an automatic braking procedure can always be aborted by the driver by the fact that, on the belt lock of the safety belt for the driver, a switching element is actuated when the locking tongue of the safety belt is engaged in the belt lock. It is thereby established whether the driver is belted-up. If the driver is not belted-up, then the execution of the automatic braking procedure is suppressed. An automatic braking procedure can only take place if the driver is belted-up. If high deceleration forces occur, then the driver is held by the safety belt and does not have to brace himself or herself. Thus, the driver can always terminate the braking procedure which is particularly necessary when the driver actuates a control pedal in a predefined manner, as constituted by the actuation of the brake pedal in the direction of its rest position--i.e. a releasing of the brake.

Automatic braking termination arrangement having a switching element

A braking pressure control device for a hydraulic two-circuit brake system with a pneumatic braking force amplifier and an antilock brake system (ABS) that operates on the feedback principle, in which a switching valve is provided for each brake circuit. Each switching valve is switchable from a position connecting the brake circuit with a pressure outlet of the braking device into a position that shuts off this pressure outlet from the brake circuit. The control device has a precharging control valve that is switchable from a position that shuts off this pressure outlet from the low-pressure inlet of the feedback pump into a position that connects the pressure outlet with the feedback pump, as well as an electronic control unit that processes the sensor signals that contain at least the information on the type of actuation of the brake pedal to generate the signals required for automatic full brake application for controlling the switching valves, the precharging control valves, the feedback pumps, the inlet and outlet valves of the ABS, as well as a control valve by which the drive chamber of the braking force amplifier can be vented.

Braking pressure control device with maximum vehicle deceleration during

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.

Growing community of inventors

Winnenden, Germany

Manfred Steiner