Controlling stability of mobile manipulators by adjusting the center of mass

A mobile manipulator, comprising:

• a manipulator base;
• at least one manipulator arm;
• and
• a control means adapted to control the mobile manipulator in accordance with a control method, the control 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 adjusting the mobile manipulator comprises adjusting a center of mass of the mobile manipulator including an adjustment of the manipulator arm configuration.

A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out a method for controlling a mobile manipulator comprising a manipulator base and at least one manipulator arm, 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 adjusting the mobile manipulator comprises instructions for adjusting a center of mass of the mobile manipulator including an adjustment of the manipulator arm configuration.