Industrial Robot Model Creation via Directional Pose Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Industrial robots face limitations in positioning accuracy due to manufacturing tolerances, measuring system accuracy, and gear backlash, which affect the alignment of the tool center point (TCP) in achieving precise poses.
Innovation Solution
A method for creating an absolutely precise robot model by moving the robot arm into various poses and measuring it while approaching from a consistent direction, accounting for gear play and backlash, allowing for the creation of two data sets for each axis to improve positioning accuracy by switching between them based on movement direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the robot arm is moved into various poses using drives via gears, then the robot can achieve programmed motion sequences, but positioning accuracy is limited due to gear backlash and manufacturing tolerances
Solution Approach 1:
The patent segments the positioning process by creating separate measurement data sets for different movement directions (approaching from plus side versus minus side). This segmentation allows the system to account for gear backlash by selecting the appropriate data set based on the direction of approach, thereby resolving the contradiction between reliable motion control and positioning accuracy.
Solution Approach 2:
The patent changes the parameter of measurement data by creating direction-specific data sets that capture the actual robot arm position accounting for gear play in each direction. This parameter change enables the control device to select the most accurate model based on the current movement direction, improving positioning accuracy while maintaining reliable motion control.
2Ease of manufacture
If conventional measurement methods are used without considering movement direction, then the measurement process is simpler, but the resulting robot model does not account for gear play, reducing positioning accuracy
Solution Approach 1:
The patent introduces dynamics into the measurement process by adapting the measurement approach based on the movement direction. The system dynamically selects between different measurement data sets (approaching from plus side or minus side) depending on the current operational context, thereby achieving high accuracy without significantly complicating the measurement process.
Solution Approach 2:
The patent performs preliminary measurements in both movement directions during the calibration phase, storing multiple data sets in advance. This preliminary action ensures that when the robot operates, the control device can immediately select the appropriate pre-measured data set, maintaining measurement simplicity while achieving high model accuracy.
3Device complexity
If the robot model does not account for gear backlash, then the control system is simpler to implement, but the actual position of the robot differs from the target position
Solution Approach 1:
The patent creates accurate copies of the robot's actual position by measuring the robot arm in various poses and storing these measurements as a robot model. By creating direction-specific copies of the position data that account for gear backlash, the system achieves high position accuracy without significantly increasing control system complexity, as the selection between data sets is automated.
Solution Approach 2:
The patent implements feedback by using the measured robot arm positions (accounting for gear play) to create an updated robot model that is fed back to the control device. This feedback loop allows the control system to compensate for gear backlash by selecting the appropriate measured data set, thereby improving position accuracy while maintaining manageable system complexity.
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for creating a robot model (17) of an industrial robot (1) which has a robotic arm (2) having a plurality of successive limbs (3-8) which are adjustable by means of drives (11-16) via transmissions (5) in relation to axes (A1-A2), controlled by a control device (10) of the industrial robot (1). According to the invention, the robotic arm (2) is moved in a plurality of poses. At least one of the limbs (4) is moved in the same first movement direction (18) by means of the drive (11) thereof at least upon approaching the individual poses. In order to obtain the robot model (17), the robotic arm (2) is measured at each of the poses thereof.