Need help-ME 4543 Mechatronics
Final hardware project: Battling Rowdy Bots
1 The objective
Your goal is to develop a wheeled robot that, in a time of 1 minutes will either; (a) push your opponents robot out of a 3-foot diameter arena, or (b) disable your opponents robot. Check this video for some examples: https://www.youtube.com/watch?v=dk8n1J9m 4Q
2 The contest • You will compete with the other teams in the class. The overall competition will be through double elimination (see http://en.wikipedia.org/wiki/Double-elimination tournament). • We will decide winner based on a single contest for a particular round. However, the last two rounds will be best 2 out of 3. • In between the matches, each team should be ready to compete again in two minutes, unless exempted by the TA. A delay in the start of the round constitutes a loss for that round. • If no one wins, the TA reserves the right to ask for a rematch or decide a winner based on other metrics. • The robots will begin the match in a random orientation which will be decided by the TA. Both the robots will start the contest in the same orientation. The robot should have a switch that the team leader turns on the moment the TA indicates the contest to start. • The decision of the TA with respect to the winners in any round is ﬁnal and binding. • The inside of the arena will be black in color and the boundary of the arena will be white in color. • The TA reserves the right to change any rule depending on the circumstances.
3 The rules for robot design and for competing
– Total robot mass should not exceed 1 kg (2.2 lb).
– The overall dimensions of the robot should not to exceed a length of 20 cm and a width of 20 cm. An articulated structure is permitted but the structure should fold at the beginning of the contest so that the robot still meets the dimension requirement mentioned above.
– No untethered and/or irretrievable projectile weapons.
– No water, liquids, chemical, biological, or nuclear weapons permitted. Any electrical, com- pressed gas/air or potentially dangerous weapons will need approval by the TA.
– The robot cannot create artiﬁcial white lines as decoys or weapons. Anything designed to go underneath the other robots should not fool the robot to go out of bounds. The TA reserves the right to declare any enhancement as un-sportsmanlike and possibly disqualify the team.
– The robots will be autonomous. No communication, physical or through wireless, is allowed once the timer starts, unless permitted by the TA.
– Defensive-only strategies will lead to elimination. The TA’s decision is ﬁnal.
– Only a single Arduino micro-controller can be used.
– LEGO parts are not allowed.
– The purchase price should not exceed $200, excluding the cost of the Arduino. However, you will not be refunded an amount which is in excess of $120. A bill of materials and supplier should be indicated in the ﬁnal report. Salvaged parts/3-D printed parts will count towards the bill of materials after putting an approximate price tag on it.
– Electrical energy limited to eight 1.5-V batteries (AA) and one 9-V battery. However, you can have as many spare batteries as you like for the contest.
4 Suggested Plan
Meeting the weekly deadlines listed below will ensure that you make steady progress in the project and do well in the project. NOTE: Before you start, please read Section 6, especially the part, “6. Personnel”. You need to ensure that all your team members are doing fair amount of technical work in the project. There are FIVE milestones which you need achieve to be eligible to participate in the ﬁnal contest. The approximate timeline is mentioned. But feel free to move ahead if you have achieved the milestone ahead of the scheduled time. Also, note that this is just a suggested timeline. Please demonstrate the milestones by Nov 11 (last lab day), else you might not be allowed to participate in the ﬁnals.
Week 1 – Oct, 14: Brainstorming of ideas for chassis selection, enhancement, and contest strat- egy. Select the chassis, the motor controller shields, and the sensors that you will need for the project. See the Section “Some Tips” to help you get started. Milestone 1: By the end of the lab, you should have a list of stuﬀ that you need to order with a bill of materials. The bill of materials should not exceed $200 excluding the Arduino. Your chassis should be within the speciﬁcation that was mentioned earlier. Show your list to the teaching assistant and get the list approved before you start purchasing. Please place an order as soon as you can because it takes a while for stuﬀ to arrive. Please combine orders with other team members to reduce the shipping costs.
Week 2 – Oct 21: Interface the motor shield to the motors and get the motors spinning at various speeds and in either direction using the Arduino. Now attach the motors to the chassis and control the motors using the code you wrote. Milestone 2: Get the wheeled robot moving around at various speeds, backward and forward, and making turns. Demonstrate this to the TA.
Week 3 – Oct 28: Interface and program the contact detecting sensors to the Arduino. Interface and program the line detector sensors to the Arduino. Milestone 3: To test the contact sensors, program the robot to move around in a random fashion. The moment the robot hits an obstacle it should turn and move in some other direction. To test the line sensors, program the robot to navigate within the battle area without crossing the white lines at the edge. Demonstrate both the tests to the TA.
Week 4 – Nov 4: Interface and program the range sensor. Calibrate the sensor for distance measurement. Display the output on the serial monitor in Arduino software. Milestone 4: To test the range sensor on the robot, program the robot to move around randomly. The robot should stop and move in another direction if it is 2 cm away from an obstacle. Demonstrate this to the TA.
Week 5 – Nov 11: Attach the three sensors on the robot body and program the robot for the contest. Milestone 5: Your robot should push a stationary (i.e. powered down, nonfunctioning) robot from the middle of the ring to out of bounds in under 90 seconds. Demonstrate this to the TA.
Contest – TBD (the week of Nov, 14 to Nov, 28): Reports due. The contest will be held in BSE Atrium (Level 1, near Einstein Bagels) Time and exact date is to be decided. You will not be able to compete in the contest if you do not meet the rules speciﬁed in section 3. Speciﬁcally, we will strictly enforce the energy limit (batteries on board), the size and weight restrictions. Even if you do not qualify for the contest, you will still get credit for doing the milestones.
Policy on missed milestones: If you miss a milestone, you can make it up on a later date. However, you should demonstrate all milestones to your teaching assistant by Nov 6 (last lab day) to be eligible to participate in the contest.
5 Some tips
These are just recommendations. You will have to customize the list based on your own needs and contest strategy. Note that UTSA is non-proﬁt and does not pay taxes. So you will not get refunded for taxes paid. If you want to buy an item without paying a tax you will need to show a tax exemption form (the instructor will provide you with the form). You can use this when you buy stuﬀ locally (e.g., home depot, intertex, radioshack). However, you will not be get tax exemption if you buy online, unless that particular vendor does not charge tax. • Here are some useful websites where you can ﬁnd useful sensors for this project; (1) https://www.sparkfun.com, (2) http://www.adafruit.com/, (3) http://parallax.com/. Electronics bought online are usually much cheaper but there are two issues with buying stuﬀ online; (i) it takes time for stuﬀ to arrive, and (ii) the cost of shipping can be signiﬁcant. Hence it is recommend that you also keep in mind that there are local stores that you can go to, especially if you are in a rush. Here are two sources:
(1) Radioshack (http://www.radioshack.com/) and (2) Intertex Electronics (http://www.intertexelectronics.com/) They have a great choices and are relatively inexpensive. Highly recommended! • You will see that there are multiple website/stores that oﬀer similar products but at diﬀerent price tags. How do you decide which one to go for? Here are some factor that might help you to decide.
1. Is the component (e.g. sensor) plug and play or needs additional wiring (e.g. soldering transistors or adding capacitors and/or resistors). 2. Is there readily available code for the component to enable ease of interfacing? 3. Is the component compatible with the hardware you have? 4. Have other people succeeded in using the component in their project? 5. Does the cost ﬁt your budget? 6. Does the component speciﬁcation meet you needs? For example, does the range sensor have adequate range?
All said, I can guarantee that you will make mistakes. For example, buying the wrong sensor. The key is to make mistakes early, so that you have time to rectify them. • Robot chassis: I have not checked if these chassis meets the size and weight speciﬁcations. You need to do this before you buy the chassis. (1) The Magician Chassis ROB 12866 from Sparkfun costs $14.95 https://www.sparkfun.com/products/12866. You will might need some additional stand-oﬀs to mount the sensors and Arduino on the chassis. (2) Emgreat Motor Robot Chassis on Amazon $12.99 http://www.amazon.com/Emgreat%C2%AE- Chassis-Encoder-wheels-Battery/dp/B00GLO5SMY Things to consider while selecting the chassis.
1. Ease of and room to mount the sensors, the batteries, and the Arduino. 2. How will the robot turn? 3. Does the chassis come with motors or you will have to buy motors yourself? 4. Does the motor ﬁt the project requirements in terms of cost and size? 5. How easy/diﬃcult it is to assemble the chassis and attach the motors? 6. How easy/diﬃcult it is to attach articulated structures on the chassis to disarm the opponent? • Motor controller: The choice will depend on how many motors you want to be controlled. Also, check the voltage/current speciﬁcations of these controllers (1) Product ID 1438 $19.95 http://www.adafruit.com/products/1438. Can control 4 dc mo- tors and 2 stepper motors. (2) Dev-09815 $24.95 https://www.sparkfun.com/products/9815. Can control 2 dc motors. Will need soldering. (3) Seeedstudio Motor shield $19.50 http://www.seeedstudio.com/depot/Motor-Shield-p-913.html
• Contact detection: Whiskers SEN-11999 $4.95 https://www.sparkfun.com/products/11999. You will have to decide the number and type based on the chassis (e.g. mounting points) and where you want opponent contact to be detected. • Range ﬁnder: There are multiple options. One sensor should be ﬁne. (1) Ultrasonic range ﬁnder SEN-00639 $25.95 https://www.sparkfun.com/products/639. (2) Infra-red range ﬁnder SEN-00895 $14.95 https://www.sparkfun.com/products/8958 (3) Ultrasonic range ﬁnder, Product ID 28015 $29.99 http://parallax.com/product/28015. Note that this sensor might need some soldering as indicated on the website. (4) Ultrasonic ranger ﬁnder Mod HC-SR04, $3.95 http://www.sainsmart.com/ultrasonic- ranging-detector-mod-hc-sr04-distance-sensor.html • Line detection: There are multiple options. Multiple sensors might be needed. (1) SEN-11769 $ 2.95 https://www.sparkfun.com/products/11769 (2) Product ID 555-27401 $9.99 http://parallax.com/product/555-27401. • Articulated structure: One strategy is to have an articulated structure controlled by a servo motor that can go beneath the opponent’s car to disable it. • Switch: You will need to have a switch that makes your robot ready for competition. An example would be a toggle switch. • Batteries: Please have surplus batteries available during the contest. Batteries need not be listed in the bill of materials.
6 Project report (due before the contest start)
How and when to submit: Email the project report to firstname.lastname@example.org and hand in a hard copy to your TA before the contest starts.
Details: Each team will submit one project report. The report should be typed in 11 point, single line spacing format in Arial font. The following sections should be included in the project. Please keep the report short and to the point. We have given a suggested page limit only for reference.
1. Table of content: (1 page).
2. Personnel: (1 page). The project is to be done by the team. It is expected that all team members share the project responsibilities. Please indicate in a table, who did what. The table should have three columns. Column 1 should be labeled “Task”. Column 2 should be the “Main personnel” who did the task. Column 3 should be the “Secondary personnel” who helped with the tasks. NOTE: This part is very important. If we ﬁnd that a team member has not contributed enough to the project, that team member can get a straight zero in the project, even if the team did very well in the contest. Each team member should have a major technical responsibility in the project. For example, articulated structure design, chassis design and/or modiﬁcations, sensor interfacing and programming, motor controller programming. Project report writing has to be a joint eﬀort and everybody has to contribute. Please
indicate who wrote which parts of the report in this section. Project report writing cannot be the only task that a team member does for credit.
3. Introduction and Summary: Brieﬂy describe the project followed by a summary of what you did (1 page).
4. Robot selection and enhancement: Describe the chassis you chose and modiﬁcations you made. Indicate which sensors and motor controllers were used and why. Have a section for each sensor and for motors and for bill of materials. We encourage ﬁgures, photos, and schematics (hand-drawn or computer generated). It is mandatory to include a bill of materials including part code if available, supplier information (e.g., polulu motors), and if possible, the web link. Note that the total cost should not exceed $200 excluding the Arduino (6 pages)
5. Robot and sensor programming: Describe how you interfaced the sensors and motor controllers and describe your strategy. Use of ﬁgures/schematics/block diagrams to illustrate strategy is highly encouraged (neat and legible hand drawings are ﬁne). It is ﬁne to include some representative code if desired, but majority of the code should be in the appendix. (3 pages)
6. Lessons learnt and suggestions: Describe using a numbered list, any lessons you learnt in the project. You should include things like, what went wrong and why, how you ﬁxed the problem and so on. Keep the description brief and to the point. You should give at least two suggestions on how you can improve based on your experience with the project. (2 pages).
7. References (if any): A youtube video of your robot doing some of the milestones, especially Milestone 5, can be included as a link, and is highly encouraged. (1 page). Here is a video by Sanya Singh, Spring 2015 https://www.youtube.com/watch?v=RXdno8ZcXkg
8. Appendix: Include code, design sketches (if not put included earlier).
The grading will be based on the following factors; achieving the milestones, the project report, and participation in the contest. The grades assigned by the teaching assistants will be ﬁnal and binding. The grading will be done in the lab AET 0.212 on Nov 11, 2016. You will be evaluated on Milestones 1 through Milestone 5.
Peer review: In addition, the lab assistant will do a peer review.
8 Returning the toolboxes
After the end of the contest, you will return the mechatronics toolboxes to BSE 2.216.