System and method for testing dynamic friction parameter

Abstract

The invention discloses a test system and method of dynamic friction parameter, the test system is characterized in that's: an absolute encoder 14 is arranged on a motor 13, a moment sensor 4 is arranged axially between a test part, a weight fixing device 6 and a locking mechanism 2, the test part is arranged at upper and lower layers of the weight fixing device, when testing, the operation of the motor is controlled by a controller, moreover the parameters including the sampling time, friction moment, rotating speed, rotating angle and motor winding current are recorded synchronously, the evaluated value of current friction parameters are set at Sigma 0, Sigma 1, Fc, Fs, Omegas, and Sigma, and then differential equation of systematic movement is solved so as to obtain the evaluated value Theta(t) of moment motor rotating angle of each sampling time, thereby respectively calculating the errors of the evaluated values of the moment motor rotating angle and the friction moment of each sampling time, the error parameters are contrasted with the set testing parameters so as to meet the required evaluated value of the output friction parameters, otherwise correction is re-made. The test system and method of dynamic friction parameter has the advantages of convenient testing and high precision. The test system is applicable for dynamic friction parameter test on various materials.

Description

Technical field [0001] The invention belongs to the technical field of testing, and particularly relates to the measurement of dynamic friction parameters, which is used to guide the design of a high-performance servo system. Background technique [0002] In a servo system, friction will be generated on two contact surfaces with relative motion or relative motion tendency. Friction reduces the stability and steady-state accuracy of the system, causes low-speed crawling, and constitutes a serious obstacle to the improvement of system performance. A large number of studies have shown that friction is a complex physical phenomenon. The friction coefficient is not only nonlinearly related to the relative speed of movement between the contact surfaces, which is called the static characteristics of friction, but also has dynamic effects such as friction memory and increased static friction. Armstrong B, Dupont P, Canudas de Wit C. "A Survey of Models, Analysis Tools and Compensation Me...

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Problems solved by technology

[0027] 2. Since both the linearization method and the frequency domain method approximate the original model, the measurement of dynamic parameters will inevitably lead to a decrease in its accuracy

[0028] 3. Since the dynamic parameters and static parameters in the original LuGre model are coupled together, there is no theoretical basis for decoupling the system based on the assumption that "the average deformation z of the bristles does not change due to uniform motion".

[0029] To sum up, there is neither a simple and effective method for identifying LuGre friction parameters, nor an instrument that can be used to obtain relevant data.

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