E138
04.2012
Patent E135 - IP Portfolio B1
Ultra-Compact Pressure Supply Unit with Inner Rotor and Ball Screw
Inventors: H. Leiber, Dr. T. Leiber
3 Core Innovations
Patent E135
Ultra-Compact Pressure Supply Unit with Inner Rotor and Ball Screw
Patent Status : Expired
Patent E135
Ultra-Compact Pressure Supply Unit with Inner Rotor and Ball Screw
Patent Status : Expired
Patent E135
Ultra-Compact Pressure Supply Unit with Inner Rotor and Ball Screw
Patent Status : Expired
Patent E87DE-SA (DE 102005018649)
Keyword: Pressure Control using adaptive characteristic mapping
Claim Features
Brake system, comprising an actuating device (30) and a control and regulating device (22),wherein the control and regulating device (22) controls an electromotive drive device (5c, 6, 7, 7a) on the basis of the movement and/or position of the actuating device (30),wherein the electromotive drive device (5c, 6, 7, 7a) displaces a piston (1) of a piston-cylinder system via a non-hydraulic transmission device, so that a pressure is established in the working chamber (4', 4a', 4b') of the cylinder, wherein the working chamber (4', 4a', 4b') is connected to a wheel brake (15, 17) via a pressure line (13),the actuating device (30) displacing the piston (1) in the event of failure of the electric motor drive device (5c, 6, 7, 7a),characterized in thatthe pressure control takes place using a characteristic map,wherein the control and regulating device (22) determines the piston position by means of at least a first sensor and the current by means of a second sensorand adjusts the position of the piston (1) using the characteristic map, the characteristic map being adapted during operation.
Abstract:
The brake system uses an electromotive piston adjustment via a mechanical transmission, whereby the pressure control is adaptive using a characteristic map adapted during operation, which represents the dependence of the brake pressure on the pedal position and is based on sensor values for piston position and motor current.
Technical Relevance:
Both the adjustable pedal characteristics (sport, normal, comfort) of the electro-hydraulic brake booster and environmental influences (air bubbles in the brake fluid, changes in the wheel brake such as slanted wear of the brake pads, friction coefficient fluctuations, knockback, fading, as well as variations in transmission efficiency) require an adaptation of the map. Typically, the characteristic map consists of several parameters (pressure-volume characteristic of the wheel brake, motor torque = f(current), variable transmission efficiency and vehicle deceleration = f(brake pressure)
The adaptation is also relevant if the ESP unit has failed/been deactivated, where the brake booster function remains fully functional. The pedal characteristics change in this case, as the brake force boost is based solely on current consumption and piston travel in the absence of the ESP pressure sensor.