Speed control for motor vehicles with microcomputer step-by-step control

US4677560A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Chi-Thuan Cao · Ditzingen, DE
• Helmut Janetzke · Hemmingen, DE
• Henning Cordes · Eberdingen, DE
• Helmut Kauff · Schwieberdingen, DE

Key dates

• Filing date: Dec 7, 1984
• Grant date: Jun 30, 1987
• Expiry date: Dec 7, 2004

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B1/04
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

The speed to be measured, either engine speed or vehicle (drive wheel) speed, is measured by a tachogenerator which trips a timer to provide a series of measurements. When the system is in use, a driver can store the actual speed at a selected moment as the desired speed. From a linearized model of vehicle speed or engine speed response to acceleration or deceleration of the engine by displacement of a control member, system parameters a.sub.1 and b.sub.1 are derived. The actual speed signal is multiplied by a.sub.1 and added algebraically (to produce a difference signal) to the desired speed signal, with the resulting signal then being multiplied by another constant derived from the system parameter b.sub.1 by reference to weighting factors p and q of a cost minimizing equation relating to the relative significance of obtaining a small control deviation and of limiting or increasing the amplitude of the control signal. An output signal is then provided by the second multiplying stage. The system can be constituted in an analog fashion or it may operate digitally by means of a microprocessor. Smoothing of the input and output signals may be provided by low-pass filtering in the ana…