# system to measure and record proximity and speed of a vehicle overtaking cyclist

Hi everyone!

I’m a final year student at my university, and for my final year project
I’ve decided to monitor the safety of vehicle overtakes on cyclists. To do
this I want to make a device which can measure the proximity of the
overtakes on the cyclist (whilst they’re cycling) and the speed of which
they overtake at.
I was hoping someone could tell me about what ultrasonic sensor is suitable
(preferably a range from 0 to about 3m), what sort of datalogger
I could use with an Arduino UNO, and some sort of system which would measure
the speed of the overtaking vehicle. I’m thinking of using 2 IR lasers (one at
the front of the bike and one at the back of the bike of a set distance)
which when triggered, would give the time between the triggers thus giving
the speed of the overtaking vehicles.

Alternatively, I also thought about using 2 ultrasonic sensors and the time between the 2 of them being tripped by the overtake could give me the speed, however since I’m a complete novice, I don’t know if an ultrasonic sensor could be used this way

I’m hoping I was clear with my message as it is quite complex and I look
forward to your replies!!

the HC-SR04 has a range of 3 to 4 metres

by sampling every 100msec you could calculate overtaking speed

a sensor on the cycle wheel could give you the speed

The Lidar-Lite will range up to 40 meters. From the change in range, you can derive the relative velocity.

You will need some other means of measuring the cyclist’s speed.

jremington:
The Lidar-Lite will range up to 40 meters. From the change in range, you can derive the relative velocity.

impressive specification! the project could carry out a comparision between the HC-SR04 and the lidar-lite in terms of cost vers range/accuracy etc

I think it would be very difficult to measure relative velocity using an ultrasonic ranger, because the beam is very broad and can't be aimed like a laser. Since the beam would be reflected from different parts of an overtaking vehicle, range measurements may be uninterpretable.

With a laser range finder you can in principle measure the relative approach velocity directly behind the cyclist, at a considerable distance, avoiding issues of acute angles.

Challenging project!

I suspect this is something more suited to a camera and image interpretation software - far beyond the capability of an Arduino.

And the camera has the advantage that it can probably identify the vehicle and maybe the driver.

...R

I like the OPs idea of measuring the time it takes for the vehicle to pass two known points (on the bike).

That simplifies the sensing enormously, to a simple ‘present or not’ in the view of each sensor. Ultrasonic might work if it has shutters to narrow the beam.

This technique will return a relative interval (speed), because the bike is/may be moving, so the cycle’s speed should be added or subtracted- depending on the relative direction of the two parties..

Distance may actually be more difficult, due to the continually varying environment...

Interesting project.

In 2006 or 2007, a Brit studied the effect of a bicyclist's lane position and other factors on the distance between himself and vehicles. He used ultrasonic sensors and a video camera. Didn't record speed, IIRC. Among the claims: cars give helmetless riders a wider berth (and vice versa). His finding in that regard has subsequently been reviewed and found wanting. This paper is an entertaining spoof on the research.

Hi Guys!

I've never done any coding before so that's why I'm here asking for Arduino Gods to help me

I'm a final year mech engineering student but my dissertation project requires me to do some coding.

I want to be able to measure the speed of an overtaking car from a cycle, I have 2 ultrasonic sensors and plan to use them like speed/light gate:

There's a sensor fixed at the back of the bike and one at the front (so the distance between them is known). When the car passes the sensor at the back, it will get triggered an a timer is set off. Then when the car passes the sensor at the front, the timer will stop and the speed of the car can be calculated using the time between the 2 sensors and the distance between the sensors. The data should then be recorded to a SD card via the use of the SD card adapter shield.

I want it so that the reading is only recorded if the back sensor is triggered first and then the front sensor.

I have 2 pretty simple HC-SR04 ultrasonic sensors to use with good range.

Is this possible and can someone set me on my way?

Hi,

bajwz:
Is this possible and can someone set me on my way?

Ok, Google: "arduino HC-SR04" and try out a tutorial with an Arduino UNO.

Yours,
TonyWilk

How do you plan to use an ultrasonic sensor to detect the arrival of a car beside your back wheel?

(Let's worry about the front wheel later).

...R

I think you may be heading for an "F" on your dissertation. Sorry, but the ultrasonic noise generated by both vehicles will be more than what is generated by your sensors. Better quantify the noise from the vehicles before continuing.

Paul

the speed of the car can be calculated using the time between the 2 sensors and the distance between the sensors.

I don't think so. For example, the sensors might detect the car when it is 10 feet away, in which case the distance required to calculate the speed is quite a bit more than just the distance between sensors. Unless the sensors reliably detect an object at a known fixed distance, there's no way to accurately determine the speed of a car.
Better quantify the detection accuracy and repeatability of the sensors before continuing.

Pete

Crosspost/repeat of http://forum.arduino.cc/index.php?topic=517959

Pete

Can’t help but wonder how much the OP’s project progressed in the almost 2 months between his or her posts?

Robin2:
And the camera has the advantage that it can probably identify the vehicle and maybe the driver.

Why would you want to do that?

wilfredmedlin:

And the camera has the advantage that it can probably identify the vehicle and maybe the driver.

Why would you want to do that?

I can't see the point in measuring the speed unless the intention is to name and shame law-breakers.

...R

Robin2:
I can't see the point in measuring the speed unless the intention is to name and shame law-breakers.

Then the camera's facing the wrong way.