Regarding script timing in Coppeliasim

[chakri]

I'm pretty new to CoppeliaSim.
I'm writing Python scripts to program the odometry data.

I'm using one script to give velocity to the rear axle of the car.

Another non-threaded script is running to calculate a dummy position and move to a new position. When using sim.simulationTimestep, it works fine, but with a different time step, it is not tracking well.

Script working fine - (with time step equal to sim.getSimulationTimeStep())

Code: Select all

import math

def sysCall_init():
    global sim, rearAxle, steering_data, rearAxleVelocity, del_t, Dummy, x0, y0, theta0, WB, startTime
    sim = require('sim')
    startTime = sim.getSimulationTime()
    rearAxle = sim.getObject('/Rear_Axle')
    Dummy = sim.getObject('/Dummy')
    del_t = sim.getSimulationTimeStep()
    WB = 0.58#0.58
    pos = sim.getObjectPosition(Dummy, -1)
    x0 = pos[0]
    y0 = pos[1]
    theta0 = sim.callScriptFunction('get_orient', sim.getScript(sim.scripttype_childscript, '/Sensors/Script'))

def sysCall_sensing():
    global x0, y0, theta0, rearAxleVelocity, steering_data, startTime, Dummy, sim
    
    rearAxleVelocity = (sim.getJointVelocity(rearAxle) *0.11)
    steering_data = sim.callScriptFunction('get_steer_angles', sim.getScript(sim.scripttype_childscript, '/SteeringController/Script'))
    steering_data = steering_data * 3.14/180
    #print(rearAxleVelocity)
    #print(steering_data)
    theta = theta0 + ((rearAxleVelocity / WB) * math.tan(steering_data) * del_t)
    x = x0 + (rearAxleVelocity * del_t * math.cos(theta))
    y = y0 + (rearAxleVelocity * del_t * math.sin(theta))
    up_pos = [x, y, 0.33]
    sim.setObjectPosition(Dummy, -1, up_pos)
    x0 = x
    y0 = y
    theta0 = theta

[fferri]

When using sim.simulationTimestep, it works fine, but with a different time step, it is not tracking well.

Why would you expect it to track fine with an incorrect time step?

Which control mode is set for the real axle by the way?