@Hatem, Thanks for your question. Unfortunately, there is no document or academic papers for the vehicle model in wf_simulator.
I will write a detailed explanation below.
The IDEAL_TWIST
model drives the vehicle according to the indicated twist
command. The vehicle position and attitude are calculated as the integrals of twist.linear.x
and twist.angular.z
, respectively.
In the IDEAL_STEER
model, the vehicle is driven according to the control_cmd
commands (steering and velocity). wheelbase
parameter is required to convert from steering to angular velocity using the two-wheel kinematics model.
The DELAY_TWIST
model uses a first-order delay model to approximate the response of the twist command to vx and wz. There are time constant
and time delay
parameters for the delay model.
The DELAY_STEER
, like DELAY_TWIST, approximates the response to control_cmd with a first-order delay model.
These delay models are the most common and simplest modeling methods and are useful for verifying the vibration and stability of closed-loop systems. You can estimate these delay parameters from the actual vehicle data. There are some pages describing the 1st order + time delay model, for example, here.
- The
CONST_ACCEL_TWIST
is a slightly special model that basically follows the velocity indication ideally, but the velocity changes with a fixed acceleration value. Therefore, there is no sudden start or stop. This model has been in wf_simulator for a long time and is used when you want to reproduce simpler and slightly more realistic behavior than the DELAY model.
I hope this could help your work. Please let me know if there is any other information you would like to know.