Engineering Education Scheme

In 1994/1995, while at the West Somerset Community College Sixth Form in Minehead, Somerset, I participated in the "Engineering Education Scheme". This scheme is run by the Royal Academy of Engineering and gives students the opportunity to ivestigate a real life engineering problem.

The team consisted of four lower-Sixth Form students, myself, Matthew Balchin, Richard Cook and Mark Russell-Stevens. We were supervised by two teachers, Mr T Griffin (a design and technology teacher) and Mr J Weedon (a physics teacher). The company we worked with was a local light engineering firm, they will not be named here for reasons of confidentiality.

Following the end of the Scheme work, the project was worked on further and entered for the 1995 Young Engineers for Britain competition. We achieved first in our group at the regional final and displayed the project at the national final at the London Guildhall.

The project was to design and build a barrier for the company's car park. Due to various physical and political limitations, many off-the-shelf designs were not suitable.

The final design was a retracting pole. The entrance to the car park was adjacent to, and in line with, an earth bank. This could be used to retract the barrier into. The intention was that the barrier would be reasonably discrete (to fit in with the rural setting), this design allowed most of the mechanism, apart from the barrier pole itself, to be hidden.

My part in this was to design and build the control electronics. The barrier could be controlled remotely by staff driving in and out. For this I used keyfob radio transmitters. This was chosen over infra-red units since line of sight would have been a problem. The barrier could also be controlled from inside the building to deal with the case of people arriving without remote controls (visitors etc.). The circuitry had to start and stop the motors at the correct time. This relied on limit switches within the mechanism. There were also several safety systems. Firstly, a switch was attached to end of the pole enabling it to be stopped if it hit and obstruction as it closed. Secondly automatic cut-offs for the motors were planned but not built. These would have broken the circuit to the motors, independently of the main control circuit if the current rose above a set threshold (i.e. the motor was jammed due to trying to push the pole too far etc.).

The initial design for the control logic was carried out using a BBC Micro and home-made interface and driver circuitry. This enabled easy modification of the logic. Later an 8051 based microcontroller circuit was used but this proven to be too problematic so a pre-build 6502 based Forth controller card was used and appropriate interface circuitry built. The code used in a demo of is available here.

The following documents related to the project are available online:

• Forth code for controller.
• Final report for EES.
• 650x Port assignments