Non-linear Measuring Apparatus for Spherical Orientation Calibration
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Solution Overview
Problem
Existing orientation devices, particularly in industrial settings, face challenges in accurately determining and maintaining the position of the tool center point (TCP) due to wear, incorrect operation, and collisions, which affects the precision of operations like welding, cutting, and gluing, especially in complex mechanical devices like wrists where parameters are not decoupled and require precise adjustment.
Innovation Solution
A non-serial kinematic measuring device with a boomerang-shaped gear member and spring-loaded linear measuring elements, coupled with a measuring adapter that converts signals into Cartesian coordinates, allowing for precise determination of TCP position with minimal joint play and elastic deformations, and is designed for harsh environments and mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If contact measurement methods are used to determine TCP position, then measurement precision is improved, but forces are exerted on the robot during measurement which can affect accuracy
Solution Approach 1:
The patent replaces contact-based mechanical measurement with optical measurement. Laser distance sensors measure distances to a measuring ball without physical contact, eliminating forces exerted on the robot during measurement while maintaining high measurement precision through optical detection methods.
Solution Approach 2:
The patent introduces a measuring ball as an intermediary object. The ball serves as a passive reference target that reflects laser beams back to sensors, enabling indirect measurement of TCP position without direct contact between sensors and the robot, thus avoiding measurement forces.
2Measurement precision
If non-contact measurement with multiple sensors is used, then measurement precision is improved, but device complexity and equipment outlay increase
Solution Approach 1:
The patent combines multiple laser distance sensors and the measuring ball into a single integrated measuring device assembly. This merging reduces overall system complexity compared to having separate sensors and processing equipment, while maintaining measurement precision through the coordinated work of multiple sensors.
Solution Approach 2:
The measuring device is designed to be universally applicable to different robot types and measurement scenarios. The same basic configuration of laser sensors and measuring ball can measure various TCP positions and robot configurations, reducing the need for specialized equipment for different applications.
3Ease of manufacture
If a measuring device with serial kinematic structure is used, then ease of manufacture is improved, but joint play and elastic deformations increase
Solution Approach 1:
The patent transitions from serial to parallel kinematic structure in the measuring device. The parallel structure with multiple measurement paths provides redundancy and stiffness, eliminating joint play and elastic deformations while maintaining manufacturability through standardized parallel mechanism components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables high-accuracy, force-free measurement of TCP position within a small working space, minimizing joint play and deformations, and is suitable for both mobile and integrated use, providing reliable data under adverse conditions.
Implementation Method 1
spring-loaded linear measuring elements
Implementation Method 2
A measuring adapter converts the signals supplied by the three linear measuring elements into path information and sends this to a computer via a standardized interface. Using a non-linear forward transformation, these are converted into a Cartesian coordinate system
Data Source
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AI summary
Non-linearly acting measuring apparatus for analysing and improving the adjustment of spherically acting orientation devices. The invention relates to a measuring apparatus for measuring small movements of a tool centre (17) of pivotable tools (16) relative to a spatially fixed frame plate (9). It is possible on the basis of the measurement results to improve the calibration of the pivotable tool (16) and thus the movement accuracy thereof. The invention comprises a measurement finger (1), which is moveable in the three axes of a spherical coordinate system and is connected, via a linear guide (3), to a boomerang-shaped transmission element (4), which is for its part connected, by way of a spherical joint (12), to the frame plate (9). Fixed to the boomerang-shaped transmission element (9) are three linearly acting linear measurement elements (6), (7), (8), which are connected, in a force-fitting manner and without play, to the frame plate (9) and the measurement finger (1), and the measurement results produced by said measurement elements uniquely describe the position of the measurement finger (1) relative to the frame plate (9) using a forward transformation. The pivotable tool (16) has, in its axis of symmetry, a positionally fixed measurement sphere (18), with which said tool engages in a dome-shaped formation (24) on the top side of the measurement finger (1) and forms a statically determinate, non-serial kinematic chain.