Hybrid optimization algorithm (GA-LM)-based parameter calibration method of articulated arm coordinate measuring machine

Abstract

The invention discloses a hybrid optimization algorithm-based parameter calibration method of an articulated arm coordinate measuring machine, and belongs to the field of precision measurement methods. According to the method, firstly, a mathematical model of the articulated arm coordinate measuring machine is established on the basis of a D-H model, then a hybrid genetic least square optimizationalgorithm (GA-LM) used for model parameter solving is designed on the basis of a genetic algorithm (GA) and a least square method (LM), and finally, the designed hybrid genetic least square optimization algorithm (GA-LM) is adopted for parameter calibration on the articulated arm coordinate measuring machine. The hybrid optimization algorithm (GA-LM) adopted in the method fuses the advantages ofthe genetic algorithm (GA) and the least square method (LM), parameter calibration can be effectively carried out on the articulated arm coordinate measuring machine, calibration accuracy is high, nosupport of external measuring equipment is needed at the same time, costs are low, and operation is simple.

Description

Technical field [0001] The invention belongs to the field of precision measurement methods, and specifically 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. It usually measures the geometric dimensions of complex parts that are inconvenient to move in large-scale processing sites. Because of its operability, flexibility and convenience, it is used in industry It is widely used in production and scientific research. Due to its tandem linkage mechanism, the measurement error of the measuring machine will be accumulated and magnified. At the same time, machining accuracy, assembly errors, wear, environmental factors, etc. will all affect the geometric parameters of each linkage, which is different from the traditional orthogonal coordinate system. Compared with ...

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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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