Modeling and parameter identification of a pneumatic constant force device

Robot-assisted material removal applications necessitate the use of active end effectors under force or compliance control for satisfactory performance. Constant force devices with pneumatic actuators, even though nonprogrammable, are the cheapest and least complicated active end effectors that are available and are expected to be useful in applications where wide changes in operating conditions are not encountered. The pneumatic circuit of such a constant force device is modeled in this paper as a prerequisite to its evaluation for robot-assisted material removal. Pneumatic model parameters are identified experimentally using an iterative maximum likelihood search. The method used here for modeling and numerical model parameter determination is general in nature and can be applied to other pneumatic systems after some modifications.