Legged mobile robot and operation control method thereof

A robot with a limb composed of one or more rotary joints (may comprise two or more degrees of freedom per joint), a high speed switching operation of the closed link status and the open link status with respect to the outside world and work object to perform, arranged minimum passive degrees of freedom (such as backlash of the reduction gear) to remove the dynamic closing errors on each limb, more appropriately manage the movable range of each limb. For example, an actuator for driving the joint even when having no means for acquiring torque information, it is possible to stably realize a high-speed switching operation of the closed link status and the open link state.