Inverse kinematics solving method for redundant robot and redundant robot and computer readable storage medium using the same

A redundant robot, comprising:

• a plurality of joints each having a servo;
• one or more robotic arms each connecting to at least one of the joints;
• a memory;
• a processor;
• and
• one or more computer programs stored in the memory and executable on the processor, wherein the one or more computer programs comprise:
• instructions for obtaining an expression of a Jacobian matrix null space of a current configuration of each robotic arm of the redundant robot corresponding to a preset end pose of the robotic arm according to the preset end pose, and obtaining a relation between an angular velocity of the joints of the redundant robot in the Jacobian matrix null space of the current configuration based on the obtained expression;
• instructions for traversing the Jacobian matrix null space using the relation, and building an energy cost function of the redundant robot based on the relation, wherein the energy cost function is a judging criterion to determine an optimal inverse kinematics solution in the Jacobian matrix null space;
• instructions for obtaining a target joint angle of each joint of the redundant robot based on the optimal inverse kinematics solution to transmit to the servo of the joint and controlling the joint based on the transmitted target joint angle;
• wherein the energy cost function comprises a gravitational potential energy cost function, a gravity compensation function, or a repulsive potential energy cost function;
• and
• wherein the energy cost function is the gravity compensation function, and the instructions for building the energy cost function of the redundant robot based on the forward kinematics algorithm comprise:
• instructions for calculating the coordinate system pose of each joint of the redundant robot using the homogeneous transformation matrix and the chain rule, and calculating the position of the centroid and a rotational axis vector of the corresponding joint according to the coordinate system pose, wherein the coordinate system pose comprises a coordinate system position;
• instructions for calculating the gravity compensation moment required for the i-th joint of the redundant robot based on the sum of the rotational axis vector of the i-th joint and a gravity moment generated by the i+1-th joint to the n-th joint, in response to the number of the joints of the redundant robot is n, wherein the gravity compensation moment required by the i-th joint wherein the gravity moment of each joint is calculated based on the mass, the coordinate system position, and the position of the centroid of the joint;
• and
• instructions for building the gravity compensation function of the redundant robot based on the gravity compensation moments of all the joints.

A non-transitory computer readable storage medium storing instructions executable on a processor to implement an inverse kinematics solving method for a redundant robot having a plurality of joints each having a servo and one or more robotic arms each connecting to at least one of the joints, and the instructions comprise:

• instructions for obtaining an expression of a Jacobian matrix null space of a current configuration of each robotic arm of the redundant robot corresponding to a preset end pose of the robotic arm according to the preset end pose, and obtaining a relation between an angular velocity of the joints of the redundant robot in the Jacobian matrix null space of the current configuration based on the obtained expression;
• instructions for traversing the Jacobian matrix null space using the relation, and building an energy cost function of the redundant robot based on the relation, wherein the energy cost function is a judging criterion to determine an optimal inverse kinematics solution in the Jacobian matrix null space;
• instructions for obtaining a target joint angle of each joint of the redundant robot based on the optimal inverse kinematics solution to transmit to the servo of the joint and controlling the joint based on the transmitted target joint angle;
• wherein the energy cost function comprises a gravitational potential energy cost function, a gravity compensation function, or a repulsive potential energy cost function;
• and
• wherein the energy cost function is the gravitational potential energy cost function, and the instructions for building the energy cost function of the redundant robot based on the forward kinematics algorithm comprise:
• instructions for calculating a coordinate system pose of each joint of the redundant robot using a homogeneous transformation matrix and a chain rule, and calculating a position of the centroid of the joint based on the coordinate system pose;
• and
• instructions for taking a world coordinate system as a potential energy zero point, and building the gravitational potential energy cost function of the redundant robot based on the mass of each joint of the redundant robot and the position of the centroid of the joint.