1. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
Design and control of compact legged-wheeled robot Project Supervisor: Dr Mohamed Kara-Mohamed Undergraduate Project 2016/17, BEng (Hons) Electronic Engineering Presented by: Zeeshan Mustafa Latif Ansari (s )
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

2. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
Abstract
This project targets at building a robotic platform capable of performing combined capabilities of walking and rolling locomotion based on different surface conditions.
Out of many walking machines, hexapod with 18 DOF (degree of freedom) is chosen as it offers best stability.
For rolling locomotion, four wheels are added under the chassis.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

3. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
Agenda
Introduction and Aim
Objectives
Overview - Scope of Project
Changes made to the Original Project Objectives
Current Status
Critical Analysis & Progress
Hardware Design (Block diagram, Robot Assembly, Design of Legs and Wheels etc.)
Software Design (Gate Selection, Algorithms, Coding)
Achievement of Objectives
Further plan towards completion
Summary and Reflections
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

4. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
Introduction and Aim
As the name states; it’s a robot with combined capabilities of legs and wheels locomotion.
Legged – a slow locomotion is for uncertain surface. Operations include Walking forward, backward, rotating (Turns) and raising or lowering the body height.
Wheeled – a fast locomotion for even surfaces. Operations include forward or backward rolling.
Aims
This project primarily aims at more generalised legged-wheeled robotic platform that can manually be switched between legs’ and wheels’ mode.
Once legged-wheeled locomotion is achieved, this platform can be modified to autonomous robot; which in future, can be further programmed to perform increasingly complex motions and functions.
Applications
Search & Rescue, reconnaissance, extra-terrestrial explorations etc.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

5. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
Objectives
Determine suitable hardware for robot structure; i.e. Microcontroller, legs, wheels, sensors and so forth.
Mechanical design of legs, wheels and sensors to further assemble the components into a robot.
Electronic circuit design and configuration of wheels, legs and sensors to aid performance.
Develop block diagram of system hardware to write program for system and algorithm(s) (high- level description) of the system software.
Derive equations to obtain mathematical model of robot.
Program the microcontroller to implement a suitable control strategy.
Basically implementing manual switch between legged and wheeled modes.
Finally adding sensors to switch it to autonomous control between two modes.
Develop appropriate test plans for circuit simulation and to check the functionality of the control strategy and robot as a whole.
Evaluate final product as an autonomous robot.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

6. Hardware Design (Block diagram)
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

7. Hardware Design (Robot Assembly)
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

8. Hardware Design(Legs and Wheels)
Leg Drawing and Dimensions for 3D Printing
Wheel Design
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

9. Software Design (Gate Selection)
A process (based on leg structure) for single leg to put up and down according to a certain order or trajectory.
Tripod Gait is famous gate, chosen for continuous stable walking motion.
Legs are divided into two pairs of three legs as shown in the picture below:
2 Pairs
1st 1,4,5 Legs
2nd 2,3,6 Legs
When 1st pair lifts off the ground, the 2nd pair supports the robot body and provides forward driving force for movement. Both pairs touch ground alternatively (Liang, 2017) .
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

10. Software Design (Algorithms and Coding)
Two methods can be used; “Inverse Kinematic” and “Forward Kinematic”.
In inverse kinematic, things are controlled on three levels:
The position (rotation) of each servo.
The position of the foot of the leg.
The movement of the robot’s body as a whole.
Whereas the forward kinematic, which is the complement of Inverse kinematic, is operated by answering where is the foot? (given the position of the joints in this leg) (Hooper, 2017).
Coding
Microcontroller is successfully checked using “Blink LED” program in Arduino.
Servo motors are tested, microcontroller successfully drives servos.
No code is yet successful in driving any leg properly.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

11. Gantt Chart (Tasks completed are “marked”)

12. Achievement of Objectives
No changes are made to the original Project plan.
Project is progressing as it was originally planned.
Parts
Description
Hardware
First four objectives are achieved.
Software
Fifth and Sixth Objectives; Mathematical Modelling and Derivation of Control strategy is in progress.
Software Implementation
Writing up program for system is started. This part is progressing in parallel with software design.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

13. Further plan towards completion
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

14. Summary and Reflections
Project is an intellectual robotic challenge. It is progressing exactly as per the first Gantt chart.
Deep research has been carried out and further research on Gate selection, Algorithms and Software Implementation will be carried out in few days.
Supervision provided on regular basis is highly professional and effective. It’s helping the author to build confidence, improve knowledge and skills and permanently adopt professional approach towards challenging engineering problems.
Weekly meetings and feedback ensure correct course of my project.
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

15. By: Zeeshan Ansari, BEng (Hons) Electronic Engineering
References
[1] Liang, O. (2017). Simple Hexapod Robot Using Arduino - Oscar Liang. [online] Oscar Liang. Available at: [Accessed 27 Jan. 2017]. [2] Hooper, R. (2017). Learn about Robot Forward Kinematics. [online] Learnaboutrobots.com. Available at: [Accessed 23 Jan. 2017]. [3] Hooper, R. (2017). Learn about Robot Inverse Kinematics. [online] Learnaboutrobots.com. Available at: [Accessed 23 Jan. 2017].
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering

16. Thank you for listening
Any Questions Please?
By: Zeeshan Ansari, BEng (Hons) Electronic Engineering