Proximity sensor project

Hello, although I have a basic understanding of electronics I am new to arduino, practical use of sensors and circuit design. I am undertaking a project that is mostly mechanical engineering/design based to create a retractable access system for large mining vehicles. This is likely to use a electronic actuator to rotate a set of steps that gives the driver access/egress to these vehicles. In the interest of safety I am looking design and install a control/safety system that will make use of ultrasonic proximity sensors to ensure the steps do now lower onto any foreign objects.

A colleague told me about arduino and it seems it would be ideal to help me design the circuit, and write the program to control the system. I also have access to an account with RS components to buy the items I need so was wanting to ask/check that my shopping list was on the right lines.

arduino board and starter kit : http://uk.rs-online.com/web/p/interface-development-kits/7154097/ US transducers / receiver : http://uk.rs-online.com/web/p/ultrasonic-proximity-sensors/2370799/ temperature sensor : http://uk.rs-online.com/web/p/temperature-humidity-sensors/3683923/

So really I am asking if these products:

1) Will work together so I can build a whole working prototype control system to measure the distance and cut off supply to an actuator should any foreign objects come too close? 2) Use the temperature sensor to increase the accuracy of distance calculations as the final product will need to work between -20 to + 50 Celsius? 3) Give me everything I need to wire it together? ( is the starter kit the best product for this?)

So, while I am not sure about the specifics of your project, it should be feasible to do something like that relatively simply on the Arduino. The basic idea behind interfacing with sensors is "How do I get a voltage out of my sensor" since this is what the Arduino's microcontroller will then read. In terms of the temperature sensor, I glanced at it and it will work, but I'm sure there are simpler solutions out there that wouldn't require building significant extra circuitry, depending on how accurate or rugged you need it to be. I'd also look around on Digikey and Sparkfun. I think you may also want modules that are already complete and will output a known signal, rather than trying to build the circuit interface yourself. It is usually cheaper that way in the long run for small quantity units.

I think my biggest concern would be that the vehicle is likely to be operating in a very dusty environment and I don't know how well the ultrasonic proximity sensors will work when caked in dirt.

Peter : The placement of the sensors will minimise the build up of mudd on the sensors (Over 1/1.5m from the ground), though they should still work with a small amount on them ( I have done research into their operation in harsh conditions). They will also be cleaned regularly along with the rest of the vehicle - but as far as I could tell they were the best type to use as IR / Laser would be less effective in such conditions.

Mirith : Cheers, the problem I have is the company I'm doing this for have an account already wit RS so it would take a lot longer to get anything from the other sites you mentioned but I'll have a look. This will only be done to build a proof of concept model, for actual production the resultant circuit/control program would be passed on to the company for them to develop into a PCB that could be used in the vehicles.

I looked about for some pre-built modules and found this :

http://www.amazon.co.uk/US-100-Ultrasonic-Temperature-Compensation-Arduino/dp/B00COD9B88/ref=sr_1_10?ie=UTF8&qid=1370600907&sr=8-10&keywords=US+sensor

guessing that would be a lot easier, cheaper and quicker to use.

Kevconaghan: I looked about for some pre-built modules and found this :

http://www.amazon.co.uk/US-100-Ultrasonic-Temperature-Compensation-Arduino/dp/B00COD9B88/ref=sr_1_10?ie=UTF8&qid=1370600907&sr=8-10&keywords=US+sensor

guessing that would be a lot easier, cheaper and quicker to use.

I think I've used that, and it will definitely work assuming the 2-450cm range is enough. It moves the problem from being a hardware issue to a software issue, which often is much easier to solve (Though not always). The arduino easily has the capability to handle the necessary calculations.

Is the temperature sensor just for compensating for the Ultrasonic, or because you need to know what temperature the area is?

The temperature sensor is just to compensate for the difference in US so I get a more accurate distance reading.