Six degree-of-freedom (DOF) measuring system and method

Abstract

This invention disclosures a six degree-of-freedom (DOF) measuring system and method. The measuring system comprises a tracking measurement device and a target. The tracking measurement device includes a processor, a camera and two rotation optical components connected with the processor respectively, which are arranged in sequence. The camera boresight and the optical axis of two rotation optical components are coaxial, and each rotation optical component can rotate independently. The target is mounted on the tested object, which contains at least three markers with known distance constraints. In addition, at least one marker does not coincide with the midpoint of the line connecting any two of the remaining markers. Compared with the prior technologies, this invention realizes a dynamic real-time measurement of six DOF for the tested object. In the process of measurement, only the target is fixed on the object. The target has the advantages of simple structure, less influence on the actual operation of the target and easy use. Meanwhile, the calculation process of 6 DOF measurement is simplified, and the real-time and reliability of the measurement method is improved.

Description

TECHNICAL FIELD[0001]This invention relates to the field of space geometry measurement, in particular to a six degree-of-freedom measurement system and method.BACKGROUND[0002]With the development of science and technology, the demand for pose measurement for industrial equipment is increasing. For example, during the operation of industrial robots, due to the manufacturing error, control accuracy and the change of environmental temperature, the accuracy of the end-effect of the robot will be greatly affected. Therefore, it is necessary to measure the end-effect of the industrial robot in real time and then feedback the position error to achieve close-loop control and finally realize the high-precision dynamic operation of the industrial robot. Besides, in the assembly process of large equipment, it is necessary to measure the spatial orientation of the parts in real time to ensure the assembly proceeded smoothly. At present, the 6 degree-of-freedom (DOF) measuring device for testing...

AI Technical Summary

Benefits of technology

This invention provides a method for measuring objects with 6 degrees of freedom in real-time by adjusting the rotation angles of two optical components. The method has the advantages of being convenient to use, minimizing the impact on the object's operation, simplifying the computation process, and being cost-effective. Additionally, the measuring system is easy to carry and has a small size.

Problems solved by technology

For example, during the operation of industrial robots, due to the manufacturing error, control accuracy and the change of environmental temperature, the accuracy of the end-effect of the robot will be greatly affected.

At present, the 6 degree-of-freedom (DOF) measuring device for testing the end-effect of an industrial robot has some shortcomings, such as the difficulty of operation, the complexity of the whole machine, the large occupation of space, the difficulty of carrying, and the high cost, which limits its application to industrial production.

Besides, the installation of the system is complex and the cost is high.

However, this method requires multiple light sources as markers and PSD to realize 6 DOF measurement of the object, so the cost of the device is high.

However, the device needs to contact with the object, and can not realize dynamic real-time measurement.

However, the measuring device is large and not portable.

Meanwhile, this measuring method deals with contact measurement for which the application range is limited.

This device has high measurement accuracy and fast response speed, but it has the disadvantages of a complex structure, complicated solving process, multiple measuring sensors, high cost of the whole machine, and it is difficult to be popularized and widely used in the industrial field.

During the measurement process, the rotation of the camera will greatly affect the image quality of the light source of the target, which directly affects the measurement accuracy of the 6 DOF of the object.

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