using ArduSimple for an autonomous formula student driving car

Q&A forumCategory: Questionsusing ArduSimple for an autonomous formula student driving car
martin.ghergut asked 1 month ago

Hi, we are from Sapienza Corse a formula student racing team,
we are develloping an autonomous car and we are looking for a gnss RTK that can help us to track the trajectory with high resolution, give us the YAW angle, position and curvature of the car.
We thought to use an “simpleRTK2B – Starter Kit LR” with another “simpleRTK2B-LR Rover”, and the configuration will be 2 u-blox antenna and a radio module on the car, and 1 u-blox antenna and a radio module at the box. We thought  to find the YAw angle with the elaboration of the 2 signals from the u-blox antenna.
But we have a lot of questions to understand if this configuration can be used in our project:
-Can we comunicate, configurate and read data from the board with a c++ code without using the u-blox application?
-What is the update rate of the data?
-There are any problems if we install the antennas on the car that is moving, vibrating? and the heigh of the antenna of 500 mm can give accuracy problems? 
-What is the start up time every time we swich on the car?
The car on that we will install the kit will be:Gajarda Driverless
Thanks!

Ardusimple Staff replied 1 month ago

Hi Martin,
– You can find sample code here: https://github.com/ardusimple/simpleRTK2B
– To calculate yaw angle within a vehicle, it’s better to use moving base functionality and let the modules calculate the vector between the antennas.
– Maximum update rate in this configuration is 5/8Hz, depending on the selected constellation
– Vibration doesn’t help, but it depends a lot of the vibration. Vibration where the simpleRTK2B board is installed is also important to be minimum.
– Startup time should be around 2 minutes.

martin.ghergut replied 4 weeks ago

Thanks for the quick reply, we have other questions to better understand how to use ArduSimple kits.
-What is the Latency time (the time that occurs between the instant of time when the GPS have a new data and the instant that the data is send by USB);
-It is possible to increase the maximum update rate using only one constellation ( for example only GPS) having an accuracy of 10/20 centimeters?

Ardusimple Staff replied 4 weeks ago

– Should be around 20-100ms. The timepulse is output at the right of the calculation, so can be used as a time mark for your system to know at which instant does the position that you just received correspond to.
– check the datasheet of zed-f9p for the complete constellation vs update rate table, yes there’s possibilities to increase data rate at a cost of lower robustness of the calculation.