In the field of aeronautical and astronautical assembly

the six–dimensional force sensors installed on the end of robot is commonly used to derive external forces

which is one of the key technologies to realize the compliance control of industrial robots

but the presence of loads will interfere the perception of external forces. To compensate the gravity of end load of industrial robots

a genetic algorithm-based gravity compensation optimization algorithm is proposed. Based on the least squared method

this method considers the influence of force sensor installation deflection angle on compensation effect

and an optimal solution model is established with the objective of minimizing the sum of squared error

by using genetic algorithm. As a result

the installation deflection angle of force sensor can be estimated without use of measuring instruments

and the accuracy of gravity compensation can be improved. In the meantime

the system errors are reduced effectively by designing specific robot measuring attitude. The experiments show that arbitrary angles of the installation deflection angle can be compensated by optimization algorithm. Compared with before compensation

maximum gravity compensation errors in each direction and average gravity compensation errors are both generally reduced.