The Gait Of A Quadruped Robot Design And Control

According to the structure design of leg joints of four legged robot, driving principle, physical features of robot’s bars, the paper established geometric model. Then combined with the basic principle of walking, the walking gait of robot is established by MSC Adams simulation.The paper mainly completed the following works:Firstly, the common movement gait of four legged animals is analyzed. Based on the ideas, the gait of a robot is determined, then the step leg sequence and motion law of four legged robot is established. This is the basis of the gait control of the four legged robot. Then, by virtual leg technology, the paper build the bridge between paired gait and four legged gait of the robot. The four legged gait can be considered as two single legged robots with difference phase, so the control model of the robot is simplified.Secondly, the goal of mechanical system design is given, and the 3D solid modeling of robot is introduced in detail, including the overall robot modeling and the main parts modeling, servo motor drive. The reason of choosing the brushless DC servo motor as the main driving mode of the main body of the four legged robot is given, then the advantages and disadvantages of several configuration modes of motor and reducer are analyzed, at last, the choice, principle and structure of the sensor are described in detail.Thirdly, the block diagram of the whole electronic control system is given. The reason that the main control system and the speed control system choose STM32F103 as the microprocessor is elaborated. The features and advantages of STM32F103 SCM are emphatically discussed. The principle and features of digital PI algorithm are introduced; two commonly used PI algorithms are also described in detail. The design of the closed-loop speed control system for the motor is designed in detail, including rotor position detection, motor speed detection, phase current detection, motor detection and communication interface design between the main control system and motor speed control system. The source and suppression of the torque ripple of the brushless DC motor are also introduced. Finally, the three-phase PWM technology is introduced.Fourthly, the MATLAB and ADMAS are introduced. The paper build a robot 3D model in ADAMS software, then save the copy of the model into the ADAMS/Simulink environment. Add build drive, force and corresponding constraints, materials. The kinematic simulation of the virtual prototype is carried out using MATLAB and ADAMS software. The robot gait transform between static walking, trotting, jumping and turning point is completed. The stable operation of these gaits is basically realized. By the judgments of the pitch angle and the roll angle, the robot can move steadily according to the plan.