A Parameter Calibration Method for Joint Arm Coordinate Measuring Machine Based on Hybrid Optimization Algorithm

Abstract

The invention discloses a method for calibrating parameters of an articulated arm type coordinate measuring machine based on a hybrid optimization algorithm, and belongs to the field of precision measurement methods. In this method, the mathematical model of the articulated arm coordinate measuring machine is first established based on the D‑H model, and then the hybrid genetic least squares optimization algorithm GA‑LM is designed to solve the model parameters based on the genetic algorithm GA and the least squares method LM. The designed hybrid genetic least squares optimization algorithm GA‑LM is used to calibrate the parameters of the articulated arm coordinate measuring machine. The hybrid optimization algorithm GA-LM adopted in the present invention combines the advantages of the genetic algorithm GA and the least squares method LM, and can effectively calibrate the parameters of the articulated arm coordinate measuring machine with high calibration accuracy, and at the same time, no external measuring equipment is needed. Low cost and simple operation.

Description

technical field [0001] The invention belongs to the field of precision measurement methods, and in particular relates to a method for calibrating parameters of an articulated arm type coordinate measuring machine based on a hybrid optimization algorithm. Background technique [0002] The articulated arm coordinate measuring machine is a non-Cartesian flexible measurement system, which usually performs rapid measurement of the geometric dimensions of complex parts that are inconvenient to move in large-scale processing sites. It is widely used in production and scientific research. Due to its serial link mechanism, the measurement error of the measuring machine will be accumulated and magnified. At the same time, machining accuracy, assembly error, wear, and environmental factors will all affect the geometric parameters of each link, which is different from the traditional orthogonal coordinate system. Compared with the measuring machine, there is still a big gap in the over...

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Problems solved by technology

However, commonly used calibration algorithms such as the least squares method LM have problems such as inability to converge when the initial value is an infeasible point in the solution process, and complex calculations with many parameters are prone to accumulated errors, while the local search ability of the optimization algorithm is poor, and it is easy to fall into local minimum

[0004] In summary, in the process of calibrating the parameters of the articulated arm coordinate measuring machine, when using high-precision measuring instruments to calibrate, the requirements for the equipment are high, the cost is high, the system is complex, and it is easy to introduce secondary errors; while using the commonly used least squares method When LM is calibrated, it has a high dependence on the initial value, and has disadvantages such as difficult convergence, many parameters, and poor local search ability.

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