The control of DLR Light-weight robot has a hierachic structure with multiple layers having different sampling rates. The inner and fastest one is the motor control loop, followed by joint control, and finally the overall control of the whole robot.
Measuring motor position, joint position and joint torque, the controller is provided with three sensor signals for each joint.
In joint mode, different control algorithms are available:
The control of the whole robot contains the interaction of all seven joints on a higher level. The following features are already implemented:
We are using a home-made tool for task planning (called "Aufgaben-orientierte Programmierung", AOP). Complex tasks are composed out of predefined modules. When starting a task, pathplanning and suitable controlers are automatically chosen.