Identification of inertia constants and joint frictions of a robot man
ipulator is achieved in situ, without dismantling operations, by means
of specific test motions. The necessary estimation of actuating torqu
es is carried out by measuring, with Hall effect transducers, the curr
ent absorbed by the motors which power the system. This identification
is accomplished by using a precise methodological order adapted to a
planar SCARA type manipulator with two degrees of freedom. The identif
ication of friction laws underscores a hysteresis phenomenon of the di
ssipative torques. This indicates that friction doesn't result from a
simple superposition of a dry friction law and a viscous damping law.
The identification results were applied with success to implementation
of optimized trajectories computed on the basis of a dynamic criterio
n. The effective minimization of the performance criterion along the o
ptimized trajectories, according to the corresponding standard traject
ories, was verified experimentally by evaluating the motor work and ac
tuator torques.