DESIGN AND CONTROL OF COMPACT LEGGED-WHEELED

ROBOT “SPICAR” Project Supervisor: Dr Mohamed Kara-Mohamed. By Zeeshan Mustafa Latif Ansari (Id: s09466807), BEng (Hons) Electronic Engineering.

1) SPICAR ROBOT

What is a Spicar robot?

The Spicar is a hybrid robot with compact 6-legged

and 4-wheeled capabilities to perform walking and

rolling locomotion.

Rationale:

In last few decades robots have taken over human in

some of their activities especially where human lives

are endangered due to the amount of risks attached

to them. Because of significant personal and

industrial demand of developing highly robust and

multifunctional robots, this project was undertaken

(Jakimovski et al., 2016).

Features:

a) Legged-wheeled robot with maximum mobility

on varying ground conditions with high speed on

wheels.

b) Good negotiating capabilities of legs.

Possible areas of implementation:

Rescue Missions, Surveillance, Space Exploration

Final Year, BEng (Hons) Electronic Engineering Project 2016 - 2017

Unit (individual component) testing

and Functional testing was

conducted. The table 1, given below,

shows results of Functional testing:

The Spicar achieved its original aim. In future, this platform can be modified and programmed to

perform increasingly complex motions and functions which are given below:

a) Addition of ultrasonic sensors to make it autonomous Spicar.

b) Interfacing with Android/Apple iOS telephones by using their WI-FI or Bluetooth technologies.

c) Adding pyro-electric passive infrared sensor can make the robot a potential rescue robot.

d) Gyroscopic sensor will enable it to sense edges of a surface thus, making it more intelligent as a system.

6) CONCLUSION AND FUTURE WORK

This project primarily aims at more generalised

legged-wheeled robotic platform that can manually be

switched between legs and wheels mode.

Objectives:

1) Project Proposal.

2) Determine suitable hardware for robot structure.

3) Mechanical design of robot i.e. Legs, Wheels.

4) Electronic Circuit Design.

5) Develop Block Diagram of system hardware for

algorithms and C programmes.

6) Hardware/Software Implementation.

7) Control Strategy Implementation.

8) Testing and Results.

9) Evaluation of Final Design and Product.

10)Autonomous Control (Optional Objective).

2) AIM AND OBJECTIVES

4) TESTING & RESULTS 3) METHODOLOGY, DESIGN AND IMPLEMENTATION

Methodology:

• Research the available locomotion systems for different

robotic vehicles.

• Set the required specification.

• Mechanical, electronic and software design.

• Build the actual system.

• Test the robot.

• Evaluate design and functionality.

• Final Project Report/Poster Presentation.

Rolling Logic

7) REFERENCES [1] Jakimovski, B., Hoerenz, M.,

Kotke, M. and Maehle, E. (2016).

Design of a hybrid wheeled-legged

robot - WheeHy - IEEE Xplore

Document. [online]

Ieeexplore.ieee.org. Available at:

http://ieeexplore.ieee.org/stamp/sta

mp.jsp?tp=&arnumber=5756943

[Accessed 4 Nov. 2016].

[2] Bonanza, R. (2017). Build a 12-

Servo Hexapod. [online]

Robotoid.com. Available at:

http://www.robotoid.com/appnotes/p

roject-build-12-servo-hexapod.html

[Accessed 24 Mar. 2017].

5) SPICAR

U

User

Robot Steering Feedback Display &

Posture Display

User Interface

Posture Calculation Task Planning

Walking Locomotion

(Gait Generation)

Rolling Locomotion

(Proportional Control)

Leg Kinematics Calculation

Wheeled Kinematics Calculation

Actuators Control On Board

Controller

Ho

st

Co

mp

ute

r

Actuators

Sensor Acquisition

Sensor Acquisition

Figure 3 Hierarchal Control Architecture

Hardware Design and Implementation:

• This involved Design and Build of Legs, Wheels, Sensors

etc. and Overall Assembly for Hardware Block Diagram.

Spicar successfully demonstrates

forward, backward and rotational

movements on both locomotion.

Hardware Block Diagram Design, Build & Assembly

Software Design and

Implementation:

• This involved Developing

Logics for Walking and

Rolling Locomotion as

follows:

Walking Logic

COMPONENTS

CYCLE 1

CYCLE 2

FINAL

STATUS

Test for Atmega2560

Microcontroller ports

OK

OK

OK

Test for Hardware

Connections

Failed OK OK

Test for Servo motors Failed OK OK

Test for DC motors Failed OK OK

The flow chart, given below, was

designed to demonstrate Walking

and Rolling Locomotion on Spicar.

Figure 6 Program Flow chart

Table 1 Functional Testing

Figure 2 Hardware Block Diagram Figure 1 Design, Build and Assembly

Figure 4 Tripod Gate and Stepping Sequence (Bonanza, 2017) Figure 5 Forward, Backward and Rotational Logic

Control

Architecture: