Frieder Dipl Ing Heintz

Mechatronic sensors in integrated vehicle architecture

Abstract At present, electronic controls and systems are in the process of becoming essential and integral parts of our vehicles whereas they were previously replacements for corresponding mechanical systems predominantly separately acting or fulfilling add-on functions. From this viewpoint, the electronic systems in the vehicle will be interconnected with each other to a much greater degree than was previously the case; for this reason, they must also be reclassified and subdivided. Accordingly, electronic signal-processing components, for example, which were previously located in central control units, will be moved to the periphery where they are mechanically and electrically integrated with the sensor or actuator directly at the point at which they are actually required (mechatronics). The varied advantages of such sensors which are also capable of digital communication by means of new connection systems (bus systems) can be seen in the concrete example of an ‘intelligent’ short-circuit-ring displacement sensor. The accuracy of this sensor can be increased considerably by simultaneously simplifying its design; the highly accurate measured signal can be transmitted in a digital form.

Vibration rejecting impact sensor, particularly to trigger a vehicular collision safety system

A moveable mass is part of a resilient spring system, in which the spring is a leaf spring restrained in a housing. Strain gauges are applied to the leaf spring, the outputs of which are integrated in a bi-polar integrator. Vibration of the leaf spring will cause sequential integration in reverse direction and, accordingly, a low output signal; deflection of the mass, for example upon on impact, will cause the integrator to provide a strong integrating signal which can trigger a collision safety system. The inherent, or characteristic frequency of the system is so selected that it is above the frequency occurring upon an impact of the sensor, or upon collision, but below the frequency occurring due to concussions to which the vehicle, or the mounting post of the apparatus on the vehicle, is subjected in use, or repair.

A NON CONTACT STRAIN GAGE TORQUE SENSOR FOR AUTOMOTIVE SERVO DRIVEN STEERING SYSTEMS

Abstract Tapping of one or more torques (ranges 10 N m and 60 N m) on the steering column of an automobile for the purpose of servo control must satisfy both high accuracy requirements and high safety requirements. A suggestion for developing a low-cost solution to this problem is described below. Strain gages optimally satisfy both these requirements: however, for cost reasons, these are not applied directly to the steering column but to a prefabricated flat steel rod that is laser welded to the torque rod of the steering column. The measuring direction of the strain gages is under 45° to the steering-column axis. The strain gages are either vacuum metallized onto the support rod as a thin film or laminated in a particularly low-cost way by means of a foil-type intermediate carrier. The relatively low output signals of the measuring resistor bridge are amplified on site (on the steering column) with an integrated electronic evaluation circuit and converted into a frequency-analog, highly interference-proof signal. Neither collector rings nor cables are needed to connect the signal output and power supply to the fixed parts of the body. Both connections are made totally non-contact by means of a very simple and low-cost rotary transformer, which surrounds the steering column concentrically and has two separate winding chambers. In this case, it is practically impossible for air-gap fluctuations and similar interferences to falsify the frequency-analog measuring signal.

Numerische Feldberechnung für die Entwicklung magnetischer Sensoren im Kraftfahrzeug

Magnetische Sensoren werden im Kraftfahrzeug vorzugsweise als berührungslose Sensoren zur Wegund Winkelmessung eingesetzt, insbesondere weil sie sehr robust sind undim Vergleich zu anderen Sensorprinzipien eine hohe Unempfindlichkeit gegen die zahlreichen im Kraftfahrzeug auftretenden Störeinflüsse aufweisen. Die Entwicklung und Optimierung solcher Sensoren nach empirischen Prinzipien ist langwierig und aufwendig. Der konsequente Einsatz numerischer Berechnungsverfahren für die auftretenden magnetischen Felder hilft, die Anzahl aufwendiger Rekursionen bei der Herstellung von Entwicklungsmustern zu verringern. Damit gelingt es, die Entwicklungszeiten zu verkürzen und die Entwicklungskosten zu senken. Gleichzeitig kann die Qualität der Sensoren einschließlich der damit verbundenen elektronischen Schaltung dank verbesserter Optimierungsmöglichkeiten erhöht werden. Unter der Voraussetzung, daß ein genügend leistungsfähiges und universelles Programm zur numerischen Berechnung elektromagnetischer Felder zur Verfügung steht, kann ein wirklichkeitsgetreues Modell des Sensors auf dem Rechner erstellt und in jeder Hinsicht variiert werden. In der vorliegenden Arbeit wird das auf dem Markt verfügbare Programm MAFIA eingesetzt zur Simulation von Wegund Winkelsensoren nach dem Kurzschlußringf KR)-Prinzip. In diesen Sensoren treten zeitharmonische Wechselfelder auf, die eine dreidimensionale Berechnung unter Berücksichtigung der Wirbelströme erfordern.

CAN, ein flexibles Protokoll auch für industrielle Anwendungen

Das ursprunglich fur Kfz-Anwendungen entwickelte CAN-Datenprotokoll und die entsprechenden Controller finden immer mehr Anwendungen auch im industriellen Sektor.