{"id":7035,"date":"2020-07-25T14:24:00","date_gmt":"2020-07-25T12:24:00","guid":{"rendered":"https:\/\/www.carrera-fun.com\/?p=7035"},"modified":"2025-01-03T14:24:23","modified_gmt":"2025-01-03T13:24:23","slug":"vehicle-speed-measurement-prototype-2020","status":"publish","type":"post","link":"https:\/\/www.carrera-fun.com\/?p=7035&lang=en","title":{"rendered":"Vehicle speed measurement, prototype 2020"},"content":{"rendered":"\n

A few months ago, I made a setup with Lego to measure time and speed. I had 3 measurement points. One measurement then put another measurement further away and a third a few cm further away. This allowed me to measure the time to make 1m standing start and have the speed at 1m.
I also used it to measure the maximum speed of the car by going full throttle.<\/p>\n\n\n\n

The setup was a bit archaic, not easy to adjust at each setup and only 3 sensors along the track. So I thought about improving the system!!!<\/p>\n\n\n\n

I ordered a while ago what to do it but I didn’t have time, at the moment, I have a little more time and I dove into the components and the code.
First encouraging tests.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

For this test, I chose the easy way, I quickly assembled the son’s First circuit.<\/p>\n\n\n\n

I have a Raspberry Pi connected to a board to distribute the connections.
Connected to it, I have a relay, a 3-diode traffic light, a temperature, hydrometry, atmospheric pressure sensor and 2 boards of 4 infrared sensors.
So I have 8 vehicle detection points.<\/p>\n\n\n\n

I have 4 points on each white strip (electric chutes) that we see at the top of the track held by the books.
distance of the measurements: 10cm, 20cm, 10cm and 20cm further on the second strip 10cm, 20cm, 10cm. Distance between the 1st sensor and the last: 1 meter<\/p>\n\n\n\n

Zoom on the mini PC and the board:<\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

We see the relay (blue) at the top which will allow to connect a controller to take control of the car. And at the bottom the T\u00b0, Hygrometry and pressure (weather) sensor<\/p>\n\n\n\n

Another view :<\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The board that manages the 4 car presence sensors: <\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

At the top we can see the traffic light<\/p>\n\n\n\n

The transmitter and receiver diodes to the left of the screws:<\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

It is fixed on an electrical chute<\/p>\n\n\n\n

Rear view:<\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Electronic equipment budget:<\/p>\n\n\n\n

Excluding Raspberry: around \u20ac10<\/p>\n\n\n\n

I tested the 4 First cars.<\/p>\n\n\n\n

I retrieved the text file generated by the program, a quick look in Excel and voila:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I tested the Donald car in 2 configurations, like the others, from a rolling start, full throttle and once from a standing start, flush with the 1st sensor. Each test has 3 attempts to get an average and eliminate any parasitic readings<\/p>\n\n\n\n

The curve at the top left is Donald’s, it’s fairly regular as readings.<\/p>\n\n\n\n

I must have a problem with the reading in zone B2-B3, because I have a shift on each curve in this zone. The sensor must not detect the car at the same level, which explains a difference on certain cars only.<\/p>\n\n\n\n

Coming soon, the test on the GO circuit.<\/p>\n","protected":false},"excerpt":{"rendered":"

A few months ago, I made a setup with Lego to measure time and speed. I had 3 measurement points. One measurement then put another measurement further away and a… <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[194],"tags":[],"class_list":["post-7035","post","type-post","status-publish","format-standard","hentry","category-articles-en"],"_links":{"self":[{"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/posts\/7035","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7035"}],"version-history":[{"count":2,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/posts\/7035\/revisions"}],"predecessor-version":[{"id":7037,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=\/wp\/v2\/posts\/7035\/revisions\/7037"}],"wp:attachment":[{"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7035"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.carrera-fun.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}