Evolution Of Buggy

Testing day

Once all of the programming, building and debugging had been completed it was test day. The first thing on test day was to set the robot to the ambient light conditions experienced in the room which meant changing the program slightly to accommodate for this. Redo any last adjustments and then our line follower was off. Having came to Test day we still realised we needed to have a lot more debugging process ,the motors did not produce enough torque, one of the circuits driving the motor board was not working correctly as one of the motors would not go backwards (not a problem for line follower mode but for symbol mode it was).

Our tests went significantly better then the Marked test from the lecturer , our robot managed to sense the line but it did not have enough torque to turn. And on the symbol mode our robot managed to only recognise the Left and Right turn but the action that they performed was not 90 degrees left and right , instead they just continually span round.

Group feedback and product development.

After the testing of the product resulted in it failing two tests, and only completing the main line following task with a little prod now and again, the group have decided that implementing the following steps would help produce a successful design:

1. Supply a greater voltage to the motors. This could be done by either using the 9V battery, the connection to the motor being controlled by a seperate motor board circuit, or running a further voltage source in parallel with the current supply; maintaining the voltage (4.5V) but increasing the current supply to the motors. This extra step would increase the torque of the motors.
2. Introduce a gearing system to the drive mechanisms. This would allow the buggy to travel at a slower speed, giving the LDR's plenty of time to sense changes in the road conditions and corrective conditions to be implemented appropriately.
3. Change the jockey wheel. The existing jockey wheel would often be mis-aligned when the buggy would try to change its direction of drive; the friction produced fighting against the motors. The installation of two jockey wheels, one in each rear corner, would elimainate this problem and allow the buggy to move more easily.

Bugguie Design

The intial and secon Prototype was made using a plastic box with some screws and masking tape. It was decided buy the team that the design of the buggies was need to be enhanced to look more professional. The team decided that we should keep the initial design but the chassis will be built by ourselves and wire the circuit boards up neatly.

For this a diagram of a the layout was required. It was drawn using Solidworks on an A3 sheet with 1:1 scale. This makes it easy to use and construct.

The chaise is a block of wood with carefully placed holes for the wiring. The wires will the run through the holes and under the chassis. This makes the wires unseen from the top and increases the look of the organisation.
As well as the wiring being neatened the team decide that the jokey wheel needs to be strengthened. This could possibly be achieved by changing the material used in construction.

First prototype.

The first prototype has been constructed. The group decided to base the design on a three wheeled basis, whereby the chassis was to be made out of plastic containers, to give rigidity and light weight. The use of the original wheels and motors help as we know these can be run effectively without too much complication. Despite this Some major problems have surfaced as a result.

• One of the worm gears is not straight and so will have to be replaced.
• There is a distinct lack of speed and manoeuvrability, however it is still able to run , so placing weight nearer the motors may help , especially when turning.
• As the group decided against lego and other "toys" as this does not show originality, the body had to be made ourselves. This is slightly tedious as nothing will fit tightly , however with the use of drills this situation is being remidied.
• Trying to find an appropriate jockey wheel that can fit with the chassis effectively and to which is effecting the turning. At the moment a lego jockey wheel has been constructed but is ideally not suitable.

Autonomous Vehicles and Robots

Introduction

Autonomous Vehicles and Robots are machines that interact with its environment. They use various types of sensors to determine the area around them. Based upon the received signal a microcontroller that has been pre-programmed to decides what should happen next. Because of the initial programming complete by humans they need little contact to perform the required jobs that they are designed to undertake.

Example of Autonomous Vehicles and Robots

There are many examples of Autonomous Vehicles. They range from UAV (unmanned aerial vehicle) to UGV (unmanned ground vehicle) and UUV (unmanned underwater vehicle) . All of these are normally used within the military. However they are not restricted to military use.

UAV (unmanned aerial vehicle)

UGV (unmanned ground vehicle)

UUV (unmanned underwater vehicle)

Oil and Gas industry's use UUV to construct detail maps of the seafloor before they start building pipework and rigs. They can also be used to survey pipes once the have been laid. In Particular UUV can allow research to be undertaken in areas that would not initial be possible by humans. Many different sensors can be attached to the UUV. For example they can determine the concentration of various elements or compounds. The absorption or reflection of light and the possibility of microscopic life.

As well as Autonomous Vehicles, robots are available and are used commonly in industry. In industry the robots are designed and used to perform repetitive task. These task would have normally ben complete by humans. By reducing the need from humans to perform the task it has reduced the amount of work a company offers but this in turn reduced the overall cost of the products they sell, however a line of robots will have a couple of operators. This is were the human interaction needs to be. If any errors occur the system can be shut and re-programmed. Even though the robots take over a high amount of labour work they provided jobs to the specialist skilled workers (i.e. the ones who can program the machine). From the industrial point of view robots are invaluable to a company that needs to turn out a high volume of products consistently.

Autonomous Robots are highly used within the car industry. Each robot will have six-axis and be mounted with several tools. A few examples of the jobs that they would undertake are:

• Drilling Holes
• Welding Panels
• Screwing
• Painting
• Cutting

The benefit of using automatic robots are they work to a much higher degree of accuracy then a human can. Not only do they have high accuracy they will complete the jobs at speed reducing the amount of time speed on the convenor belt in construction. They will have an a high initial start-up cost but this can easily be overturn with a quick turn around time with reduced number of rejects. Also if a company wish's to produce a new product they can easily be re-programmed where as a human would need to be retrained with time taken to familiarise them with the process of construction, hence increasing the value of having robots.

Autonomous Robots Working on Cars

Conclusion

Autonomous Vehicles and Robots are extremely cleaver machines that have been pre-programmed by humans to do repetitive or dangerous tasks. They have been invaluable to all types of industries and occupations. Without them a large amount of what we have now would not be available - for example oil rigs that are build more than 500m under water. Using robots has increased the quality of products that can be produced which should to more reliability and confidence in company to produce quality made as well as designed products.

Initial Testing - Motor Torque

Initial Testing - Motor Torque

Today Initial testing was undertaken on the motors provided. This was to identify if the motors that have been supplied are of high enough torque to potential move the buggy along.

This was carried out buy a simple test of mounting the motors and attaching some wheels. To simulate the weight of the batteries/ circuit board etc. The mains power supply was used. See images and video bellow.

Test Rig

Close Up

Wheel Spinning

As can been seen in the video the initial test was successful, however some issues did arise.

It became apparent that the wheels that have been supplied do not have enough friction to handle the power of the motors (see video below). To overcome this issues we simply placed some duck tape onto the wheels to gain more traction. As a result the test rig moved much better(see video below).

Wheels with Duck Tape

Initial Buggy Design

Further developments to undertake from test rig.

See if the design will be stable under loading

See if the design will work with the designated sensor

Increase the friction of the wheels

Circuit board/motor/battery layout.