1. BIPED ROBOT Guide : Dr. Jisha V. R. Student Members : Syamprasad K. R. Vaisakh P. Alfaz A. Muloof P. 1 COLLEGE OF ENGINEERING, TRIVANDRUM ELECTRICAL & ELECTRONICS ENGG.

2. Objective To design a Bipedal Walking Robot which attains stability autonomously. 2 3. The Biped Robot Obtaining human-like robotic walking has been a long standing goal of robotic locomotion. Key principle is ZMP (zero moment point) The idea is that, in order to attain stability, the stationary leg should have no net torque acting on it. 3 4. Block Diagram 4 Box encasing the electronic circuit Hip servos Knee servos Ankle servos 5. Methodology The entire walking cycle has been divided into different steps: i) Lift phase ii) Transfer phase iii) Landing Vukabratovics Idea 5 6. The Biped 6 7. Challenges Selection of Servo Torque for various joints Power Supply Current Requirement of 6 servos Aluminium Built Clamps- their orientation and joints, screws, washers 7 8. Challenges Mechanical Stability of Structure Autonomous Stabilization Proper Calibration of Angles Timing of all Servos Platform And Coding Initially coded in PIC Shifted to Arduino Platform 8 9. Components Arduino Mega 2560 Servo Motor Hitec HS 645MG HS 5495 BH Regulator ICs 7805 7806 9 10. Components Aluminium Clamps C-short C-long L clamp Aluminium and Iron plates Power Source 9v Duracell (Alkaline) 12v, 5AAC to DC Adapter 10 11. Servos Torque Calculation Weight of L clamp = 8.8 g Weight of Long C clamp = 23 g Weight of Short C clamp = 16.2 g Weight of Foot = 35.1 g Aluminium + 109.3 g Iron Weight of Platform and Load = 250 g Total(including allowance) = 600 g Distance of CoF from Torque end = 15 cm Max. Torque required = 0.6*15 = 9 Kgcm 11 12. Servos Hitec HS 645 MG Ultra Torque Torque : 7.7 Kgcm(4.8v) 9.6 Kgcm(6.0v) Speed : 0.2 sec/60 deg Hitec HS 5495 BH Torque : 6.4 Kgcm(6.0v) Speed : 0.17 sec/60deg 12 13. Controller 13 Microcontroller : Atmega2560 (Arduino Mega 2560) Operating Voltage : 5v Input Voltage : 7 -12v Digital Pins : 54 Analog Pins : 16 PWM : 15 Flash Memory : 256 KB Clock Speed : 16 MHz 14. Basic Servo Control Circuit 14 15. Algorithm Access servo library from Arduino. Define servo object. Assign and initiate Servo Pins. Set angle either through code or through analog input. Scale the input , if necessary, and write it to servo pin. Call required delay. 15 16. Implementation Various combination of clamps were used to implement the mechanical structure. The servos are seated on universal servo brackets and the servo discs are fastened using brake wire. All the servos were checked and their zero deg. Positions were marked prior to mounting. 16 17. Implementation The circuit was implemented and was calibrated by checking the maximum angle at which the ZMP remained at the centre of foot. The ZMP check was done using Potentiometer input for servo control, and in few cases, manually changing the servo position. 17 18. Completed Project 18 19. Road Ahead A surveillance camera can be mounted on the top of it. Walking assistance in the case of Paralysis or Muscular Breakdown. Manoeuvrability on multiple terrains 19 20. References M. Vukobratovic and D. Juricic, Contribution to the synthesis of biped gait, IEEE Trans. Biomed. Eng., vol. 16, no. 1, pp. 16, 1969. Philippe Sardain and Guy Bessonnet, Forces Acting On A Biped Robot. CoP- ZMP, IEEE Trans. Systems, Man And Cybernatics. ,Vol 34, no 5, Sept. 2004. 20 21. 21 THANK YOU!!