design and control of a 6 dof biped robot
abstract
this thesis is composed of the following five parts: construction of a 6 degrees of
freedom (dof) biped robot, control system design, analysis of forward
kinematics and inverse kinematics, walking pattern planning, and pid control
implementation.
the 6 dof biped robot is built with aluminum plates, aluminum angles,
wood, and rubber materials. it has two legs, two feet, and one trunk, each leg
having three joints: hip, knee, and ankle. all joints are actuated by gear head dc
motors with built-in encoders.
a microcontroller-and-pc-computer-based control system is designed for
the biped robot. the control system consists of actuators, sensors, controllers,
and a pc computer. the actuators are the gear head dc motors with h-bridge
circuits as drivers and the sensors are incremental encoders built in the dc
motors. the controllers used are two microcontrollers, one for each leg. the
microprocessors read and process joint angle measurements from the encoders
and then transmit them to the pc computer. at the same time, the
microcontrollers receive control signals from the pc computer and transfer them
to the h-bridge circuits to control the robot joints. data transfer between the
microcontrollers and the pc computer is implemented by two rs232 serial
communication channels. a control algorithm and walking pattern planning are
carried out on the pc computer.
both forward kinematics and inverse kinematics are analyzed based on
the d-h representation for the biped robot.
foot trajectories and hip trajectory are calculated by using the 3rd order
spline interpolation method. desired trajectories for joint angles are determined
by the inverse kinematics. simulation is performed to demonstrate the walking
pattern.
pid controllers are designed for controlling the biped robot to walk
according to the designed walking pattern. the proposed pid controllers are
implemented on the biped robot.
collections
- retrospective theses [1604]