Fast and "soft-arm" tactics

One crucial requirement for robot manipulators is their accuracy and rapidity in performing tasks when required. Two approaches can be used to deal with the problem of achieving the best performance, under the condition that safety is guaranteed throughout the task execution. One is the DM2 actuation approach and another is the variable stiffness transmission (VST) approach. The former consists in dividing torque generation among two actuators, of which one is devoted to low-frequency components of the required torque supply and the other is designed for the high-frequency part. The latter approach consists in allowing the passive compliance of transmission to vary during the execution of tasks. Applications of both approaches show that VST allows the most flexibility and potential performance.