Truck Loading Position and Speed Sensor

Are the trucks the same, as in the length from the nose to the bucket?

Is it possible to pull the truck through the dumping area? as in like a car wash?

Is it possible to use a multiple dumping chute so the truck stops at a pre-designated position and the chute's dump in that position?

are you able to move the dumping chute above the truck so the truck stops at a known location and the chute moves along the length of the truck? This would be say on the end of a conveyor and that moves from start of dump to the end, as the conveyor moves at a known speed.

Well, it's not really designed for this but a radar level transmitter might work. Select one with a tight beam pattern. It's output is actually distance but it should be a simple matter to calculate the speed based on distance over time, right?

An alternative is a laser level transmitter. Different principle but same idea (to me at least).

Lastly, you could install several photo sensor along the truck's path. Install the sensors at precise distance intervals so that as the truck breaks each beam, you can calculate the speed by counting the time it takes to break successive beams.

Confusing question...insufficent detail.

You could be looking for solution suggestions, or looking only for input on your idea, or both. It's hard to tell which. You say, in effect, you need something to (help you) "calculate" speed; but you could mean you want something to calculate for you and provide a reading? Here are some Q & A which will perhaps invite suggestions for ways to get it done.

1. It appears your "system" will be permanent-fixture mounted, not mobile &or truck mounted. True?
2. Your system will be for one time, or some time, use but not for continuous, repetitive use?
3. Your system will be for testing purpose only in order to arrive at a "standard" datum; or to actively monitor trucks passing under the chute?
4. You want to manually record data for later, manual calculation?
5. You want the truck operator to interact/not interact with the system.
6. You want the system to autostart based on truck position or motion? Or be manually started? Same for stopping the system?
7. Your system will be sheltered/unsheltered from...weather, cargo, dust, etc?
8. Your system will be standalone? Networked?

That's all for starters. On first look, this could be a job for camera or video/web camera

Thanks.

I'd recomend getting in touch with MDLs Laser modules sales people, this sounds like a possible application they could help with. They have many modules that could be used for such an application. All contact details should be available on www.MDL.co.uk.

Welcome aboard! As noted by others, the question seems insufficintly detailed. Do you need an instantaneous speed reading? Apparently the truck is moving for even load distribution, so is a weight sensor a possibility? Some feedback will refine the conditions and likely get you better answers!

What are you loading into your truck, is it Grain, Gravel, or other? I come from a farming background and we constantly move grain around, so it was important we got a full, evenly distributed load for more efficient grain transport. Do you have numerous trucks that are getting loaded or are you wondering about your own personal truck. The reason i ask is if the number of trucks isn't a large one, you may want to consider mounting a camera(s) on your box and putting a monitor in the cab to watch as the truck gets loaded. If there are a large number of trucks this may not be a viable solution so you may want to go back to a sensor that would calculate your speed. In my experience I have never run across anything that could fill my truck fast enough and evenly for me to move a truck at a constant speed (no matter how slow I move the truck, any slower and it would stall) but I've never moved anything other than grain on a small scale farm.

as all above said, do you hope to locate the truck or measure its speed?

if you position you truck, you have to use three devices. if you hope measure speed, how much accurancy do you want?

I guess you hope to install a device, when the truck pass in 30m range, you can find and meaure its speed?

I dont think doppler device is a best bet for so slow speed.

because that will need very very narrow band. only pll may do the job.

Truck scales for weighing in both modes dynamic and static one were implementing such technique for weighing, positioning car over platform, speed metering, type of truck identification. Load cells built in road bed (and sometimes contact sensors) had been used for that.

Idea is simple, as axes' of any truck along with its number and formula(configuration 1-1, 1-2, 1-2-3) could be related to standard it could be used for above mentioned goals.

I do not suggest you to use load cells but contact sensors(tight enough to be switched by a heavy lorry) or a simple photo sensor relay's set which could read bypassing vehicle's wheels(axes). Of course here's preferable to employ a controller and timer(s). Data Base of trucks' axes dimensions and formulas could be developed gradually during maintenance.

Hi All,

Thanks for all the input, sorry for the lack of detail.

Attached is a sketch which might make things a bit clearer.

Basically, I am looking for a device that could be placed ~20m in front of a truck and give me a repeatable reading on the distance. This will allow me to indicate to the driver when to stop under the chute. Guide rails would position the truck directly in front of the sensor. This device needs to be suitable for outdoor use and not overly sensitive to dust rain etc. Options include, Lazer, Microwave and Ultrasonic (but please give your 2 cents).

After stopping, the driver would be prompted to move forward to achieve the desired filling.

The driver will need a speed read out so that he does not move too fast and create a gaps in the load.

If the distance sensor is accurate enough, I can calculate the trucks speed based on the rate of change of distance and indicate it to the driver.

Hope this answers some questions.

Cheers,

RobW

Note: Approx. filling speed of truck is <2km/hr NOT <5km/hr as shown on the sketch.

Would a mechanical switch hooked up to an electrical readout do you any good?

Having as given your schematic diagram I would suggest you to think throughly to secure abslolutely foolproof level of safety for the project. As truck has to move slowly under uploading I think simple mechanicaly driven switches (as Envoroman suggested) look as quite good and reliable decision. At least you can apply these switches as additional option to another set of more sophisticated sensors.

First switching means that first axe went by.

Second switching allows to measure speed.

Third switching means that process of uploading has to be start.

Forth switching(or predefined time span) means that bulk material uploading has to be stopped.

I would put there traffick lights along with specailly painted color (lightened) marks on the side wall for driver. Maybe CCTV for facility's operator.

Think about sensors which stop uploading immediatelly if material spills out.

Truck scale are suitable for such application, but I can't insist. It's up to you.

I was thinking of something like a walkalator. A large conveyor or moving track on the ground where the truck could just ride as the conveyor moved along. Yours is much simpler. GA.

regards,

Vulcan

Thank you for the kind words. It would be similar to the semi automatic car washes, where a wheel of the car is pulled through the wash machines.

The variable speed hydraulic winch would allow the operator to fine tune the opperation by watching the fill rate on the TV camera.

Me also found your decesion as most profound here. But I'm not sure for would be that implemented by one engineer. This is a project for specialized company. Winch has to move a heavy truck(without brakes) smoothly. It's not a trivial control task.

Yes, it's a good idea: discrete (sectioned) dumping, dispense program (either operator), TV/camera set.

But let truck's going under driver hand being stopped either by marks or opertor's/light's commands.

The braking should not be a problem, as the speed is probably going to be very slow. An additional wheel speed "bump" should solve any concerns. Perhaps an air horn to alert the driver would help.

I do accept all your arguments as ground based.

Horn signal is one more good idea. I think driver should be precautioned don't hold his right foot laying on gas, though.

When they made EastLink here in Victoria (Australia) they filled semi-trailers with hot asphalt to be transported to the road laying equipment.

The trucks drove into an enclosed hopper bay where they were filled, the whole trailer was inside the hopper bay during the filling (and the gasses vented)

I don't think the trucks moved during filling (was a bit hard to tell over the dirt embankment they built)

They had several hoppers inside the "station" that filled each truck.

I have seen elsewhere, filling trucks, they have 1 filler, multiple hoppers, and a feed-screw distributing the material inside the hoppers, once filling was completed, the truck drove out and the base of the hopper scraped the top of the heap flat.