Robot Safety Sensors Mounted on Rotating Joints
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Solution Overview
Problem
Existing safety devices for robots often impair productivity by limiting movement speed unnecessarily and require a large number of sensors to monitor static spatial areas, compromising efficiency and safety.
Innovation Solution
A safety device with a plurality of sensors mechanically coupled to a rotating body part, monitoring adjacent spatial sectors that rotate with the body part, allowing for efficient and fail-safe control of the machine's movement based on sensor signals, reducing the need for static sensors and minimizing unnecessary speed reductions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large number of static sensors are used to monitor spatial areas around the robot, then safety coverage is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies the dynamics principle by mounting sensors on the rotating body part instead of using static sensors. As the body part rotates, the sensors dynamically sweep through different spatial sectors, allowing a small number of sensors to monitor the entire surrounding area over time. This dynamic monitoring approach replaces the need for multiple static sensors positioned around the robot.
2Reliability
If safety zones are monitored with static sensors, then safety is ensured, but productivity decreases due to unnecessary speed reductions
Solution Approach 1:
The dynamic sensor arrangement allows the system to distinguish between areas currently occupied by the rotating body part and areas that are temporarily unmonitored. This enables more precise safety control, where speed reductions are only applied when actually needed, rather than continuously limiting speed due to static sensor coverage gaps.
Solution Approach 2:
The system uses feedback from the rotating sensors to dynamically adjust safety responses. By continuously monitoring which spatial sectors are currently being swept by the sensors and what objects are detected, the control system can make real-time decisions about speed adjustments, avoiding unnecessary limitations when no objects are present in the monitored sectors.
3Area of stationary object
If static sensors monitor the entire area around the robot, then complete coverage is achieved, but the number of sensors and system complexity increase
Solution Approach 1:
The patent employs a dynamic monitoring approach where sensors mounted on the rotating body part sweep through different spatial sectors as the body part rotates. This allows a small number of sensors to cover the entire surrounding area over time, eliminating the need for multiple static sensors positioned around the robot to achieve complete spatial coverage.
Data Source
AI summary
A safety device for safeguarding a danger zone of an articulated robot having a body part which, during operation, executes a rotary movement about an axis of rotation during robot operation and thereby defines a current direction of rotation. The safety device includes multiple sensors and an evaluation and control unit. The sensors are configured to be mechanically coupled to the body part such that the sensors move together with the body part in the current direction of rotation during robot operation. The evaluation and control unit is configured to control the rotary movement of the body part in response to sensor signals from the sensors.