Camera-Based Robot Arm Joint Tracking Without Encoders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensor systems for monitoring and controlling robot arms lack precision and efficiency in determining pose and movement parameters, particularly in unstructured environments, and require multiple sensors and complex wiring, which increases system complexity and cost.
Innovation Solution
A sensor system utilizing high-resolution imaging sensors, such as cameras, to monitor and control kinematic chains by identifying characteristic features like optical markers and textures, allowing for visual pose estimation and joint position determination without the need for internal sensors or complex wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional joint sensors (encoders) are built into each joint of the robot arm, then precise position and velocity measurements are achieved, but system complexity and wiring requirements increase significantly
Solution Approach 1:
The patent extracts the sensing function from the robot arm joints and relocates it to an external imaging sensor system. Instead of building encoders into each joint, the system uses external cameras to capture images of the robot arm, processes these images to determine joint positions and velocities, thereby eliminating the need for complex internal sensor wiring while maintaining measurement precision
Solution Approach 2:
The patent replaces mechanical/electronic sensor systems (encoders, motors with built-in sensors) with an optical imaging system. The imaging sensor captures visual information, and image processing algorithms substitute for traditional mechanical sensing mechanisms, eliminating the need for complex wiring through the robot arm joints
2Manufacturing precision
If multiple sensors and processing electronics are integrated into the robot arm, then control accuracy is improved, but the robot arm becomes heavier and more expensive
Solution Approach 1:
The patent extracts all sensing and processing electronics from the robot arm structure and relocates them to external systems. The robot arm itself becomes a passive mechanical structure without embedded sensors, dramatically reducing its weight while external imaging sensors and processors maintain positioning accuracy through visual feedback
Solution Approach 2:
The patent creates a virtual model of the robot arm by capturing its visual appearance through imaging sensors. This digital copy or visual representation is used for control and monitoring purposes, eliminating the need for physical sensors in the robot arm while maintaining control accuracy
3Reliability
If traditional sensor systems with wiring through the arm are used, then reliable position feedback is obtained, but the system requires complex cable management and is less flexible
Solution Approach 1:
The patent replaces mechanical wiring systems with wireless optical communication. Imaging sensors capture images that are transmitted and processed externally, eliminating the need for cables running through the robot arm joints, thereby improving flexibility and adaptability while maintaining reliable position feedback through visual data
Data Source
Figure 1a
Figure 1b
Figure 2
AI summary
A method for determining the joint positions of a kinematic chain (1), e.g. a robot (105), by using only an imaging sensor (4), e.g. a camera, and a computing unit (5), wherein characteristic features (3), e.g. patterns, on the links and joints of the kinematic chain (1), are identified and the joint positions are calculated from these visual measurements. The control of the robot can therefore be performed without the use of joint encoders. A sensor system (100) for monitoring the status of a kinematic chain (1), e.g. of a robot (105) is provided. The sensor system (100) includes a computing unit (5) and at least one imaging sensor (4), e.g. a camera, operably connected to the computing unit. The imaging sensor (4) may be mounted to the kinematic chain (1) or may be mounted in the surroundings of the kinematic chain and monitors at least a part of the kinematic chain and/or the surroundings of the kinematic chain. The computing unit (5) determines a pose and/or movement parameters of at least one element of the kinematic chain by analyzing an output signal of the imaging sensor, in particular by analyzing characteristic features and determines a rotational joint position by analyzing the characteristic features.