Omnidirectional wheeled humanoid robot based on a linear predictive position and velocity controller

A humanoid robot with a body joined to an omnidirectionnal mobile ground base, and equipped with:

• a body position sensor and a base position sensor to provide measures,
• actuators comprising joints motors and at least 3 wheels located in the omnidirectionnal mobile base, with at least 1 omnidirectional wheel,
• extractors for converting the measures into observed data,
• a controller to calculate position, velocity and acceleration commands from the observed data using a robot model and pre-ordered position and velocity references,
• means for converting the commands into instructions for the actuators,
• wherein the robot model is a double point-mass model, and wherein the commands are based on a linear model predictive control law with a discretized time according to a sampling time period and a number of predicted samples, and expressed as a quadratic optimization formulation with:
• a weighted sum of:
• a base position objective,
• a base velocity objective,
• an objective related to the distance between the CoP and the base center, CoP being the barycenter of contact forces between the robot and the ground,
• with predefined weights and a set of predefined linear constraints which are:
• a maximum velocity and acceleration of the mobile base,
• a CoP limit.