Robot Abnormality Detection Through Integrated Motion Sequences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing abnormality detection devices for movable apparatuses, such as multi-axis robots, face challenges in accurately detecting abnormalities when the movement of joint shafts is small, as the change in disturbance torque may be insufficient to exceed a constant threshold, leading to inaccurate detection.
Innovation Solution
An abnormality detection device and method that includes a control unit with a signal input unit to detect anomalies using a detection signal from sensors, which executes an integrated action by adding a necessary action to a predetermined routine operation to enhance the detection of disturbance torque changes, allowing for accurate abnormality determination regardless of small movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a constant threshold is used for disturbance torque comparison, then the detection method is simple, but the abnormality detection accuracy deteriorates when movement is small
Solution Approach 1:
The patent applies dynamics by transitioning from a static constant threshold to a dynamic threshold that adapts based on operation content. The threshold is no longer fixed but varies according to the robot's operational state, allowing the detection system to maintain high accuracy across different movement conditions while managing complexity through intelligent adaptation rather than multiple fixed systems.
Solution Approach 2:
The patent changes the parameter of the threshold from a constant value to a variable value that depends on operation content. By making the threshold parameter dynamic and context-dependent, the system can accurately detect abnormalities whether the robot is stationary or moving, resolving the contradiction between simple detection methods and accurate detection across varying operational conditions.
2Productivity
If the robot executes routine operations with small movement, then the disturbance torque change is small, but the abnormality detection becomes inaccurate
Solution Approach 1:
The patent implements feedback by using the operation content information to dynamically adjust the threshold for disturbance torque detection. The system feeds back the operational context to the detection mechanism, allowing the threshold to adapt to current conditions. This enables accurate abnormality detection during routine operations with small movements while maintaining high productivity, as the feedback loop continuously optimizes detection sensitivity based on actual operational state.
3Measurement precision
If the threshold is increased to detect small changes, then abnormality detection sensitivity improves, but false detection increases when movement is minimal
Solution Approach 1:
The patent resolves this contradiction by making the threshold parameter dynamic rather than fixed. Instead of using a uniformly high threshold that causes false detections during minimal movement, the system adjusts the threshold parameter based on operation content. When the robot is stationary or moving minimally, the threshold adapts to appropriate levels, preventing false positives while maintaining high sensitivity for detecting actual abnormalities during active operations.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An abnormality detection device of detecting an abnormality of a robot (101) which executes an operation such as welding on a target object, includes a control unit (51) including a signal input unit to which a detection signal is input, the detection signal being obtained when a state of the robot (101) is detected by a sensor (13), so that the control unit (51) detects an abnormality of the robot (101) in accordance with the detection signal. The control unit (51) outputs a control signal to the robot (101) so as to execute an integrated action in which a necessary action necessary for detecting an abnormality is added to a predetermined action in which the operation is not executed on the target object. The control unit (51) detects the abnormality of the robot (101) in accordance with the detection signal detected when the integrated action is executed.