WHAT HAPPENNED IN MAKING ROBOT

I and my friends are doing assingment on robotic class. There are some kind of robots built such as line follower, wall follower and robotic arm.

There are some pattern in all the assignment. All the system must contain power supply, sensor, processor and actuator. Sensor may use some signal conditioner for processing by processor. In my environment, the processor is usually from AVR ATMEGA class. The design can also be divided into the hardware and software. Hardware include the electrical and mechanical design. Software include the low level which access the hardware directly and the high level which only process the information.

Here are some problem usually met by a robot builder. This problem could aso be happening on electical circuit developer.

– UNCONNECTED GROUND VOLTAGE REFERENCE

This is usually happen when you decide to use more than one battery and each PCB uses one battery. Using one battery does not need additional ground cable because all the circuit is in the negative pole of battery while using different battery requires the ground connection to make the same votage reference for all the circuit. Without the connection, the data transfer will be unable to be performed.

– INVERTED BATTERY POLE

this can cause a really serious problem in the system, especially for the processor and other chip. The problem will be like sudden overheating or burned circuit. If you use voltage regulator such as 7805 and you give negative input voltage, the IC will be overheating and produce smoke before exploding. To prevent this inverting suply problem, you can use diode connected in series from the power supply(battery, adaptor) to the regulator. The diode will only allow current flow with the right polarity and block the other polarity. The other way is to use standarized connector for power supply. The standarized connector is usually designedto prevent such problem. The other tips for designing is to use some standard rule like black colour for ground cable and so on.

– BAD MECHANIC DESIGN

Here is The problem which occur on my team. I use PCB to create a gearbox with the hole size and distance is by manual measurement. The problem is the measure ment is not really precise and there are miscalculating happen which cause unconnected gear.we spend two whole night to fix the gearbox and finally produce a fair quality gearbox. Some of my friend use gearbox bought form a toy or robotic kit. of course it is easy on assembling but it will cost more.

– BAD PCB CONNECTION

this is the annoying problem!! this usually happen because you needto take something off your PCB. on the process the printed metal is usually damaged. The other cause is component placement that is not exactly put on the PCB.this will increase the possibility of damaging the PCB. if the printed circuit is damaged it will usually be broken more and more. the most annoying effectis when your system stopped functioning in the middle of operation. To prevent this problem, get yourself used to do good soldering and make a neat design.

– NOT USING YOUR OWN DESIGN

This problem will occur when you copied the circuit from someone who designed for a really specific system. The circuit will not always be aplicable for your system or you need to design your system to be fit in the circuit.. for some team copied some of my circuit design, they will have some trouble in assembling the hardware. You better use your own design because you will know how it works and it will really help you in troubleshooting process.

– DATASHEET!!

for some people who are not used to electrical component and circuit, reading datasheet can be really useful becauseall the information you need is usually in the datasheet. even so, reading datasheet is complicated enough if you are not used to it. there are many question about component operation which is answered clearly on the datasheet, so GET USED TO IT!!

– MAKE GRAND DESIGN FIRST!!

The error on system implementation, such as the choosing the component, placement and the work process is usually because there are no grand design of the system. when you create someting by doing it per part without thinking the interconnection, the system will not be optimal. you should make your grand design and then the details per part.

I know that the problem mentioned above usually the simple things but this is really happening. So let us be a good designer. Good luck To all the robot builder and developer!!