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Biological Inspired Robot Project Gerard Simon Prosper Abstract The third project for the MMAE 232 class is a bi- ological inspired robot which was able to travel au- tonomously 4.9 meter on the designated track. Au- tonomous means the robot cannot be touched while on the track. Inspiration from nature had to be used as the basic idea for the robot. The inspiration for this robot was a snail. The robot was built with Medium Density Fibreboard ( MDF ) and was propelled by Hitec-425BB servo motors. The robot successfully moved 4.9 meters but the movement was not straight and can be improved. 1. Introduction The idea for the robot has to be inspired and inno- vated by nature. Biological inspired design was learn- ing from nature and making a mechanism which is sim- pler and more effective since nature does not always use the simplest and most efficient way to the result. The challenge for this project was letting the robot to move 4.9 meters independently in a straight line on an incline after being turned on. The track had a slight incline and decline on it. The change is height was no more than 3.1 mm. A robot with legs were required for this project, wheels were not allowed to be used as moving mecha- nism. Materials that were being provided in this project are screws, 1/4 inch MDF board, 1/8 inch MDF board, AA sized battery pack, an Arduino board, and Hitec - 425BB servo motors. Other materials were allowed to be used if needed. A picture of the Biological Inspired Robot is shown (see Fig.(1)). 2. Concept Generation and Evaluation In order to get the best design among the two de- signs from the group members which are an Ant or a Snail, a decision matrix (see Table 1) was used. Three criteria were taken into consideration in this decision matrix and the three criteria are reliability, ability to balance, and efforts to program. The first design was Figure 1. Final Production of Robot Figure 2. Ant Sketch

Bio-Inspired Robot

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Biological Inspired Robot Project

Gerard Simon Prosper

Abstract

The third project for the MMAE 232 class is a bi-ological inspired robot which was able to travel au-tonomously 4.9 meter on the designated track. Au-tonomous means the robot cannot be touched while onthe track. Inspiration from nature had to be used as thebasic idea for the robot. The inspiration for this robotwas a snail. The robot was built with Medium DensityFibreboard ( MDF ) and was propelled by Hitec-425BBservo motors. The robot successfully moved 4.9 metersbut the movement was not straight and can be improved.

1. Introduction

The idea for the robot has to be inspired and inno-vated by nature. Biological inspired design was learn-ing from nature and making a mechanism which is sim-pler and more effective since nature does not always usethe simplest and most efficient way to the result. Thechallenge for this project was letting the robot to move4.9 meters independently in a straight line on an inclineafter being turned on. The track had a slight incline anddecline on it. The change is height was no more than 3.1mm. A robot with legs were required for this project,wheels were not allowed to be used as moving mecha-nism. Materials that were being provided in this projectare screws, 1/4 inch MDF board, 1/8 inch MDF board,AA sized battery pack, an Arduino board, and Hitec -425BB servo motors. Other materials were allowed tobe used if needed.

A picture of the Biological Inspired Robot is shown(see Fig.(1)).

2. Concept Generation and Evaluation

In order to get the best design among the two de-signs from the group members which are an Ant or aSnail, a decision matrix (see Table 1) was used. Threecriteria were taken into consideration in this decisionmatrix and the three criteria are reliability, ability tobalance, and efforts to program. The first design was

Figure 1. Final Production of Robot

Figure 2. Ant Sketch

Table 1. Design Matrix for Two DesignsDesign Weighted Ant SnailReliability 2 + +Ability to Balance 3 + +Efforts to Program 3 - +Total - 2 3Total Weighted - 2 8

Figure 3. Analysis for Ant

a hexapod based on ants. Three of the legs moved atthe same time and has a very good ability of balancinghowever it is harder to code since it used up 12 servomotors. The second design is biological inspired by asnail. The design for the snail only requires one servo.This will be less time consuming to design in Inventorand to construct. It also has a good ability in balancingand is easier to be coded.

3. Analysis

Initially, an ant (see Fig.(2)) was the inspiration forthe first biological inspired design. The ant design re-quired 12 servos to function well. Based on rough cal-culation (see Fig.(3)), this design was not acceptable asthe required distance for the servo to move the legs andwhat actually the servo can do in reality, the differencewas not acceptable. Even though Gait analysis (seeFig.(4)) and movement stability analysis (see Fig.(5))showed good results, the design had to be rejected com-pletely as it was time consuming and the servo couldnot achieve the required torque to produce.

Figure 4. Gait Analysis for Ant

Figure 5. Stability Analysis for Ant

The second design was simpler and the inspirationwas a snail. Only one servo was required to power thesnail robot and based on initial calculations, this designwas acceptable. The gait analysis (see Fig.(6)) showedpositive results. A design was done in Inventor (seeFig.(7)) to give a better idea on where changes need tobe done so that the robot agrees to the functional re-quirements and be able to move completely on its ownon the designated track.

In order to ensure that the servo will be able tomove the robot forward, the below calculation wasdone:

F = ma (1)

Where F is the force required to move the robotforward, m is the mass of the robot which is 0.25 kilo-gram and a is the gravitational force which is 9.81m/s2.

Figure 6. Gait Analysis for Snail

Based on the equation, the Force will be 2.45 Newtons.To find the torque required to move the robot for-

ward, the below equation was used:

τ = r×F (2)

Where τ is the torque required to move the robotforward, r is the radius which is 0.008 meter and F isthe force required to move the robot forward which is2.45 Newtons. Based on the equation, the Torque willbe 0.0196 N m.

The torque produced by the servo is 0.320 N mwhich is more than 0.0196 N m. Hence, the servo isable to move the robot forward.

4. Experimental Results

The robot successfully completed the designatedtrack. It took sometime to finish the track and did notmove as straight as expected but nevertheless, the robotdid what it was required.

5. Discussion

Once we finished designing the robot in Inventor, itdid not take long to construct it as it was a simple de-sign. On a normal surface, the robot worked perfectlymoving forward. But difficulty was encountered whenit tried to move on the track whereby the robot was notmoving forward. After some evaluation, it was discov-ered that the Drag Box,(see Fig.(8)) had to be removedand something else had to be added to provide traction.Thereafter, foam was used (see Fig.(9)) in replace of theDrag Box with a holder so that the foam would alwaysbe at a certain angle to allow for grip on the track sur-

Figure 7. Completed Drawing of Snail in Inven-tor

Figure 8. Snail Drag Box

face. Once the foam was in place, the robot managed tomove over the track. It was not moving smoothly andsteadily but eventually, the robot crossed the finish lineall in one piece. If a bigger piece of foam is used and anextra servo is added to the design, the robot will be ableto complete the track in a timely manner.

6. Conclusions

It can be concluded that this robot meet the func-tional requirement and completed the designated track.With the given time and resources, the robot is as effi-cient as it could be. Furthermore, the design could workbetter if the suggested modifications were made.

Figure 9. Foam Addition