Industrial Robot Touch Control via Dynamic Model Torque Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing industrial robot control systems require external torque sensors and reference measurements to detect commands, which are cumbersome and ineffective during arbitrary robot movements, necessitating an improved method for touch-based control without these dependencies.
Innovation Solution
A method utilizing a robot controller with a dynamic model and resolver-based feedback control to detect external torque behavior, allowing for command execution without external torque sensors or reference measurements, by determining and comparing torque indications to execute corresponding robot functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external torque sensors are used to detect commands, then command detection reliability is improved, but device complexity increases
Solution Approach 1:
The robot controller uses its own existing dynamic model and resolver feedback control to detect external torque behavior, making the system self-sufficient without requiring additional external torque sensors. The controller leverages its inherent computational capabilities and existing sensor data to perform command detection.
Solution Approach 2:
The patent replaces the mechanical sensor-based torque detection system with a computational approach using the dynamic model. Instead of relying on physical torque sensors to measure external forces, the system uses mathematical modeling and signal processing of existing feedback control data to infer external torque behavior.
2Measurement precision
If reference measurements are used for torque detection, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The dynamic model is pre-computed and stored in the robot controller, containing all necessary information about the robot's mechanical properties, inertia, and kinematics. This preliminary preparation allows the controller to detect external torque behavior during arbitrary movements without requiring real-time reference measurements or calibration procedures.
Solution Approach 2:
The system transitions from using fixed reference torque values obtained through separate calibration measurements to using dynamically computed torque values from the dynamic model. This allows the system to adapt to any robot configuration and movement, eliminating the need for predefined reference measurements.
3Measurement precision
If external torque sensors are positioned at robot joints, then command detection accuracy is improved, but device complexity increases
Solution Approach 1:
The robot controller's dynamic model and resolver feedback control system serve multiple functions: they provide both the standard position control functionality and the external torque behavior detection capability. This multi-functionality eliminates the need for dedicated torque sensors at each joint, as the same computational infrastructure serves both control and detection purposes.
Solution Approach 2:
The dynamic model acts as an intermediary that translates existing resolver feedback data into external torque behavior information. Instead of directly measuring torque with sensors, the model computes the expected torque based on robot dynamics and compares it with actual feedback, thereby inferring external torque behavior through this computational intermediary.
Data Source
AI summary
A robot and method for controlling an industrial robot, which has a first robot arm, a second robot arm, a joint defining a kinematic pair between the first and second robot arms, an actuator for generating relative movement between the first and second robot arms, and a robot controller for controlling the movements of the actuator. The method includes the steps of: determining a presence of a first torque indication at the actuator to be interpreted as a first command to the robot controller; repeatedly obtaining an external torque value (τext) to obtain an external torque behavior; comparing the external torque behavior with the first torque indication; and executing a robot function corresponding to the first command upon detecting that the external torque behavior corresponds to the first torque indication. The obtained external torque behavior depends on a reference torque value (τref) obtained from a dynamic model of the robot.