Controlling Stability of Mobile Manipulators by External Stabilizing Devices

A mobile manipulator, comprising:

• a manipulator base;
• at least one manipulator arm;
• at least one external stabilizing device;
• and
• a control means adapted to control the mobile manipulator in accordance with a method comprising:
• determining a current configuration of the mobile manipulator including a manipulator arm configuration and a manipulator base configuration;
• determining a desired movement trajectory of the mobile manipulator;
• determining a current zero-movement points (ZMP) trajectory comprising the location of one or more current ZMP of the mobile manipulator based on the current configuration of the mobile manipulator and the desired movement trajectory;
• determining a desired ZMP trajectory of the mobile manipulator, wherein each ZMP is located within a support polygon of the manipulator base;
• and
• adjusting the mobile manipulator such that the current ZMP trajectory corresponds to the desired ZMP trajectory;
• wherein the mobile manipulator further comprises at least one external stabilizing device and wherein the step of adjusting the mobile manipulator comprises the step of supporting of the mobile manipulator by the external stabilizing device.

A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out a method, the instructions comprising:

• instructions for determining a current configuration of the mobile manipulator including a manipulator arm configuration and a manipulator base configuration;
• instructions for determining a desired movement trajectory of the mobile manipulator;
• instructions for determining a current zero-movement points (ZMP) trajectory comprising the location of one or more current ZMP of the mobile manipulator based on the current configuration of the mobile manipulator and the desired movement trajectory;
• instructions for determining a desired ZMP trajectory of the mobile manipulator, wherein each ZMP is located within a support polygon of the manipulator base;
• and
• instructions for adjusting the mobile manipulator such that the current ZMP trajectory corresponds to the desired ZMP trajectory;
• wherein the mobile manipulator further comprises at least one external stabilizing device and wherein the step of adjusting the mobile manipulator comprises the step of supporting of the mobile manipulator by the external stabilizing device.