we are planning to conduct an experiment where we have to control the gap size between two driving cars. I am afraid we have to control the gap size manually, since we don’t have access to the vehicle’s sensors or actuators (both cars would be equipped with ACC). Therefore, I am looking for a distance sensor which I can connect to a Laptop (or Raspberry Pi) to feedback the current gap size to the driver. We are aiming for gaps between 2-5 seconds on 40-60 km/h (i.e. 10-80 meters). We were looking into dGPS, however most systems feature a measurement frequency of only 1Hz which would be too low to properly control the gap. I assume Lidar would be the way to go. Can someone recommend a sensor for this setting?
Thank you in advance!
Hi @Phips! Welcome to the RobotShop community!
Very interesting idea!
Most of our LIDAR products should be easily usable on a laptop or RPi… our used with a bare-metal device like an Arduino connected by USB to the laptop or RPi!
This requirement of distance would limit you to some of our higher end sensors, but it is certainly doable. It should also be noted that cars have licence plate which are great reflective targets for LIDARs to be aimed at and provide accurate data from!
Definitely not fast enough. I’d expect something along the range of 100+ Hz would be best for such an endeavor.
Certainly! Here are some potential sensors that could work in this setup depending on your requirements:
- Benewake TF03 LIDAR LED Rangefinder IP65 (100 m) [RB-Ben-08]
This one has a 100 m range, high refresh rate and an IP65, which means it could be mounted in front of the car (aiming at the other’s licence plate, for example) and survive splashes of water and such. Accuracy is ±10 cm (< 10 m) and 1% at longer ranges, so about ±80 cm @ 80 m. Of course, you may get better results on a highly reflective surface. It has a range of 70 m (10% reflectivity) to up to 180 m (90 % reflectivity). It also should work well at up to 100 kLux (bright direct outdoor sunlight).
- SF30-C Laser Rangefinder - 100m [RB-Plx-317]
This model has a range of 0-100 m on natural targets and 0-175 m on reflective targets. The resolution can be reported from 0.03 - 1.0 m, but the accuracy is reported as ±0.1 m (± 10 cm) for 70 % reflective target. If you can target a licence plate reliably you will most likely get better than this.
- ILM 150m Laser Rangefinder [RB-Mrp-01]
This last contender is a professional grade sensor with an accuracy of 10 cm over the full range of 0-150 m (90% reflectivity) and 0-75 m (18% reflectivity). That being said, their refresh rate is a bit slower being around 9 Hz. It comes with a full IP67 rated case.
For your case, I’d most likely recommend the RB-Plx-317 as the best option for features and price.
Good luck with your project and let us know how it goes!