Measuring geometrical parameters of non-standard involute spur gears for humanoid massage robot with reverse solution

In order to improve the transmission precision of non-standard involute gear for humanoid massage robot, a reverse solution based on mixed iterative algorithm was proposed to measure non-standard parameters of involute gear. Firstly, using the mixed iterative equation constructed by the involute equation and Aitken accelerating convergence algorithm, the base circle radius is solved. Secondly, the reference circle radius and pressure angle of reference circle are computed using the iterative equation of the pressure angle on base circle. Finally, the module of gear is solved according to the relationship between module of gear and reference circle radius. Experimental results show that the error of reversing the base circle radius is 0.0019mm with the proposed algorithm and the reverse accuracy is improved by 1μm compared with Newton iterative algorithm. When the gear parameters are non-standard, the pressure angle reversing error of the reference circle and reference circle radius error are 0.0005 degree and 0.0015mm respectively using the proposed algorithm and the pressure angle reversing angle and reverse accuracy is improved by 1 degree and 2mm respectively compared with the parametric test algorithm. Therefore the proposed algorithm could achieve the precise reverse solution to non-standard parameters of involute gear.