Mercedes-benz Aktiengesellschaft

Albrecht Eckl

Bernd Knoff

Franz Brugger

Manfred Steiner

Martin Klarer

Siegfried Rump

Joachim Nell

Hans-Georg Riedel

Christoph Steffi

Brian Douglas

Wolfgang Kiesewetter

Manfred F Brugger

Fredy Eckstein

Ulrich Stoll

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 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. If, for example, current through a solenoid valve does not lie within specific acceptable limit values or pedal travel which results from the actuation is not determined at the brake pedal, the device concludes that an operational fault has occurred

Monitoring method and device in automatic braking process

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.

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Stuttgart, Germany

Albrecht Eckl