Camera Optical Unit Backlash Compensation via Digital Control

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Solution Overview

Problem

Camera systems in surveillance monitoring face inaccuracies due to mechanical play caused by tolerances and thermal expansion, which existing technologies partially address through backlash compensation but require mechanical solutions that reduce efficiency.

Innovation Solution

A camera system with a digital controlling device that calculates and executes compensation movements for the optical unit's backlash-based relative movement, adjusting based on the center of gravity's position relative to the swivel range, using an actuator and sensor device to minimize mechanical play and gravity influences without continuous mechanical drives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If mechanical backlash compensation is used to improve positioning accuracy, then positioning precision is improved, but device complexity and mechanical efficiency deteriorate

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmechanical complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical backlash compensation mechanisms with a digital control system. The controlling device receives position information from the sensor device, calculates compensation movements digitally, and adjusts the actuator accordingly. This eliminates the need for complex mechanical compensation structures while achieving improved positioning accuracy through software-based compensation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If continuous mechanical drives are used to compensate for mechanical play, then positioning accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic backlash compensation rather than continuous mechanical drive. The controlling device calculates compensation movements based on position information detected by the sensor device, and applies compensation only when necessary (e.g., when position deviations exceed thresholds). This periodic digital compensation reduces energy consumption compared to continuous mechanical adjustment while maintaining positioning accuracy.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3949372B1Camera system and method for positioning an optical unit of the camera system
Publication Date: 2023.08.23 ROBERT BOSCH GMBH

AI summary

The invention proposes a camera system (1) comprising an optical unit (2), a mounting device (10) for moveably mounting the optical unit (2) on a mounting surface (11), an actuator (3) for generating an actuation movement, wherein the actuator (3) is coupled to the optical unit (2) and/or to the mounting device (10), so that the optical unit (2) is moved relative to the mounting surface (11) around a swivel range (12) when the actuator (3) is actuated, a sensor device (7), wherein the sensor device (7) is adapted to detect a position information of the optical unit (2), a controlling device (4) for controlling the actuator (3), wherein the controlling device (4) is adapted to determine a compensation movement based on the position information for compensation a backlash-based relative movement between the actuator (3) and the optical unit (2), wherein the optical unit (2) comprises a center of gravity (13), wherein the center of gravity (13) is arranged out of the swivel range (12), wherein the compensation movement is varied in dependence of a position of the center of gravity (13) relative to the swivel range (12).