Mercedes-benz Aktiengesellschaft

Daimler-benz Ag

Robert Boschgmbh

Dailmer-benz Aktiengesellschaft

Franz Brugger

Bernd Knoff

Albrecht Eckl

Manfred H Burckhardt

Manfred Steiner

Martin Klarer

Siegfried Rump

Hans-Georg Riedel

Andreas Faulhaber

Heinz Leiber

Eberhard Schnaibel

Joachim Nell

Alfred Sigl

Richard Zimmer

Franz Moser

Wolfgang Kiesewetter

Hellmut Krohn

Horst Grossner

Dieter Roller

Walter Kostelezky

Christoph Steffi

Brian Douglas

Wolfgang Korasiak

Thomas Ruhl

Ulrich Stoll

Siegfried Schlosser

J/u/ Rgen Paul

Friedrich Solleder

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

The invention relates to a method for setting a trigger threshold value for an automatic braking operation. When the actuating speed of the brake pedal exceeds a threshold value, automatic braking operation is initiated, and a brake pressure is increased relative to the brake pressure corresponding to the position of the brake pedal. During each brake actuation a relation is formed between the pedal travel of the brake pedal and the derivative of the vehicle deceleration with respect to the pedal travel. A correcting value is defined from this relationship and the threshold value for automatic braking is determined as a function of a preset threshold value and the correcting value.

Method for determining a trigger threshold value for an automatic

A method checks a vehicle brake system rapidly and reproducibly to measure the correlation between the brake pedal travel and the retardation produced. A test-bed routine is called up in the control unit. During the operation of the test-bed routine, the functioning of the brake system is checked. For this purpose, a pressure difference is produced in the vacuum brake booster. The brake booster pressure difference produces a brake pressure in the brake master cylinder, and a pedal travel corresponding to this brake pressure simultaneously arises. The retardation can either be measured at the rollers of the test bed or is derived from continuously measured wheel speed values. A retardation value can be determined for each wheel as can a correlation between the pedal travel and the retardation from the measured values in the presence of different brake booster pressure difference. The process can average the values measured at the individual wheels.

Vehicle brake system checking method

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

The invention relates to a method for defining the initiation sensitivity of an automatic braking procedure, in which method the threshold value for the initiation of an automatic braking procedure is reduced as a function of the pedal distance which has been traversed. The object of the invention is to ensure that in the event of actuation of the brake shortly after the automatic braking procedure has terminated, the automatic braking procedure is again initiated rapidly and easily. For this purpose, the initiation threshold value for the automatic braking procedure is reduced within a time period after the satisfaction of the interruption criterion.

Method for controlling the initiation sensitivity of an automatic

The invention relates to a method for carrying out an automatic braking process for motor vehicles with an anti-lock brake system. An automatic braking process is triggered when it is detected by the anti-lock brake system that at least one wheel of an axle of the vehicle reaches the locking limit. The brake pressure for the axle of this wheel starts to be controlled by the anti-lock brake system. However, a further increase in brake pressure at the wheels of the other axles of the vehicle is possible since, because of the load distribution of the vehicle and because of the distribution of braking force, the locking limit of the said wheels is not yet reached. According to the invention, a further increase in the brake pressure at the other axles takes place during the automatic braking process.

Method for automatic braking of motor vehicles with an anti-lock brake

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.

Method for terminating a motor vehicle automatic braking process

In a drive slip control device for a road vehicle, which is provided with an anti-lock system operating on the pump-back principle and having a return pump of the anti-lock system associated with the brake circuit of the driven vehicle wheels used as the auxiliary pressure source for the drive slip control, for braking a vehicle wheel tending to spin. When the drive slip control is activated, the main brake pipe of the brake circuit of the driven vehicle wheels is shut off from the brake unit by means of a drive slip control valve. The return pump is activated and is shut off from the brake unit until the drive slip of one of the driven vehicle wheels exceeds a threshold value whose magnitude lies between the drive slip required value and threshold response value. The brake pressure control valves of the brake circuit of the driven vehicle wheels are driven into their closed position by means of this anticipatory activation of the return pump. This causes high pressure to build up in the main brake pipe, which is limited to a value of the anti-lock braking system and of the brake equipment by means of a pressure limiting valve, which is then available for an introductory brake pressure build-up phase of the drive slip control on the vehicle wheel requiring it. An additional outlet valve, by means of which the return line of the rear axle of the anti-lock system can be directly connected to the brake fluid reservoir, can be provided for controlling the pressure reduction phases.

Drive slip control device

An anti-lock brake system (ABS) for a road vehicle is equipped with a wheel slip control system (ASR) and a hydraulic dual circuit brake system having front axle/rear axle brake static brake circuits, one brake circuit being allocated to the driven (rear) wheels of the vehicle and one to the non-driven (front) wheels. The system has two high-pressure pumps, one for each of the two brake circuits and which, in control phases of the ABS, brake fluid can be fed into the output pressure spaces of the brake unit and wherein the high-pressure pump allocated to the rear axle brake circuit is also utilized as auxiliary pressure source for the ASR. At the front axle brake circuit, the ABS operates on the feedback principle and at the rear axle brake circuit it operates on the discharge principle.

Anti-lock brake system

An automotive engine forming part of a motor vehicle is controlled to avoid slipping or spinning of a driven wheel by controlling the maximum rate of change of fuel which can be supplied to the engine, for example, by limiting the speed of deflection of a throttle flap (6) driven by a servo motor (7). The deflection speed, limited for example by a voltage divider (14) can be controlled as a function of operating parameters of the engine or the vehicle, for example, vehicle speed (V.sub.F), engine speed (n.sub.M), engine loading or a percentage of engine loading, actual wheel slip, actual angle or deflection position of the throttle flap, and the like. Further, non-linearities between deflection of an operator actuated pedal, such as a gas pedal (1) and actual deflection of the control flap (6) can be compensated for, for example, in a difference forming circuit (9) providing an output error signal for the servo motor (7) or by software, e.g. by recourse to non-linear characteristics stored in a table or graph. The duration of limiting can be determined by timing circuit connected to a terminal (p) for example, on the voltage divider (14). The system can be instrumented electrically (FIG. 2) or, for example, hydraulic-electrically (FIG. 3).

System for controlling the fuel supplied to an automotive engine

A clutch operating cylinder for a pressure-medium operated clutch which is arranged in the power train of a vehicle, is operable either by the clutch pedal or via a electronically controlled system, for example an anti-slip regulating system, has a housing divided into two chambers. In these chambers there are, apart from the release piston, two further pistons and a spring having a clutch characteristic, such that the electronic control is never able to clutch further than is specified by the clutch pedal, the clutch pedal bites when it is operated subsequent to electronically controlled engagement, and it is possible to use both the clutch pedal and the electronic control to declutch further when the clutch has only been partially declutched.

Clutch operating cylinder for a pressure-medium operated clutch

In a vehicle equipped with a propulsion control system combined with an anti-blocking system, a pressure reservoir provided as a brake pressure supply-source which can be charged by means of the return pump of the anti-blocking system, whereby the charging operation is valve-controlled so that the feed from the return pump is directed into the pressure reservoir during pressure-reduction phases of the propulsion control system, the pressure reservoir can also be charged, outside the control phases of the propulsion control system, either by operating the driver's brake pedal or by automatic activation of a charging circuit accompanied by the operation of the return pump.

Installation for charging a pressure reservoir provided as a pressure

A system for controlling the propulsion on motor vehicles which not only enables the output torque of the drive unit of the vehicle to be utilized in an optimum manner in critical driving situations, especially under extreme road conditions, but also endows the vehicle with good stability and enhanced driving safety. A comparator is provided, in a propulsion control system which is triggered by at least one presettable or permanently preset threshold value of the speed of the vehicle, and generating an output signal causing the drive torque to be reduced, as soon as this threshold value is exceeded and a signal is present, which indicates that an individual wheel brake is being activated and/or that one of the driven wheels is tending to spin. The threshold value of the speed of the vehicle, which value governs the control process, is preferably regulated in accordance with the transverse acceleration which acts on the vehicle whenever it follows a curved path.

System for controlling the propulsion on motor vehicles

A drive control device for a motor vehicle with rear axle drive and equipped with an anti-blocking system. As part of a rotational speed sensor arrangement provided to determine the state of movement of the vehicle wheels, each of the non-driving front wheels has an associated rotational speed sensor and the two rear wheels have a common rotational speed sensor, which measures the rotational speed of the propeller shaft in the transmission system. A hydraulic actuator provided for brake pressure control corresponds in construction to that of a 4 channel anti-blocking system. These components are utilized for both the drive control and the anti-blocking control. An electronic control system of the drive control device, which processes the output signals of the rotational speed sensors, initially activates the right-hand rear wheel brake, as soon as a driving wheel starts to spin. If the vehicle does not accelerate in consequence or if, indeed, there is a deceleration of the vehicle, switching occurs to the left-hand driving wheel brake either with a time delay or immediately. If necessary, both driving wheel brakes are activated with a time delay and the engine torque withdrawn. In the case of travel around a curve, the control cycle is introduced by braking the driving wheel on the inside of the curve.

Growing community of inventors

Winnenden, Germany

Franz Brugger