# Mathematical Modeling and to Carry out a Prototype Helpmate Differential Drive Robot for Hospital Purpose

## Article excerpt

Abstract. Robots are quite adjustable with the human society. Especially in industries, hospitals, school-college, military in everywhere. But developing countries are much more behind with this. Food, cloths, shelter, education, health in every sector they are struggling. The authors choose one of the sectors of the basic needs, where robots can perform as a helpmate for hospitals or clinics. The helpmate uses wheel encoders and sensors information to steer. This paper presents mathematical modeling, hardware and electrical design and implementation of prototype differential drive helpmate robot, with a complete navigation system is aided by four types of behaviors which help to reach its destination successfully.

Keywords: Mobile robot, Helpmate, IR sensor, BBB.

(ProQuest: ... denotes formulae omitted.)

1 INTRODUCTION

Mobile Robot is a robot which can move one place to another. Research on mobile robot has placed highly emphasis on perception, modeling and navigation. As a result, robots have been designed considering their limitations. Ultimately robots are limited less by planning and more by dynamic behavior. The simplest case of mobile robots is wheeled robots, which capable of dynamic behavior (Xu and Ou, 2005). Wheeled robots comprise one or more driven wheels and have optional caster wheel and possibly steered wheels. Most designs require two motors for driving a mobile robot (Braunl, 2006). According to the wheel configuration mobile robots can be classified as differential driven, Omnidirectional, car-like, Synchro-drive (Balkcom and Mason, 2002; Arvin et al., 2009; Song and Byun, 2006; Cho and Ryeu, 2006; Fox et al., 1996).

A helpmate differential drive prototype has been made which has two motors mounted in fixed position on the leftand right side of the robot with one caster wheels (Braunl, 2006). The helpmate will able to carry the meal trays, sterile supplies, medicine, medical reports, records, and provided necessary information to the patient to update them. Odometry-based navigation system enhanced by infrared (IR) sensor, which able them to deal easily with cluttered, unstructured environments.

The helpmate robot is arranged with five infrared sensors. Two of them are side of the wheels and rests of them are in front of robot. The helpmate is powered by 8AA batteries with two motors and wheel encoders can be controlled via MATLAB on its embedded micro-computer, the BeagleBone Black (BBB).

The simulator emulates the helpmate, which is a timer object. The execute function inside the supervisor has been called at every time step. The supervisor gathers the sensor information from the robot. Then passes the sensor information to the execute function of the controller alone with an estimate of the robot's position and orientation. Linear and angular velocity of the robot has been computed by the execute function and then converted to the leftand right speeds of the robot and passed back to the robot. Supervisor also updating the estimate of the helpmate's position in orientation and the whole process in repeated at every time step (De la Croix, 2014).

The Helpmate has been made such a way that doctor and nurse can reprogram it and interface with it very easily. Designed helpmate robot is a mechatronic system, which is not only a marriage of electrical and mechanical systems and is more than just a control system; it is a complete integration of all them (Bishop, 2006).

The paper is organized as follows. Section 2 presents the mathematical approach of differential wheel drive, wheel encoder, Odometry and IR Range Sensor. Section 3 introduces the transformation from robot coordinate frame to the world coordinate frame. Section 4 educates the navigation system of helpmate robot. Section 5 describes the mechanical and electrical design of the helpmate robot respectively. Section 6 concludes the paper.

2 HELPMATE KINEMATICS: A MATHAMATICAL APPROACH

Kinematics is the most basic study of mechanical system behavior. …

Search by...
Show...

### Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.