How can I move a vehicle using speed and steering angle?

Question

I want to drive a vehicle in x and y coordinate area with range from (0,0) to (6000,5000). I am using Visual Components (using Python API).

On input I have speed data and steering angle of wheels from Simulink. For example speed of 30 (0.25 m/sec) with the steering angle of wheels from 35 to -35.

I can use something like x = speed * COS( steeringAngle ) and y = speed * SIN( steeringAngle ) while adding up the values of x and y together respectively for each loop.

But the problem is it goes in one direction. If the vehicle turn and comes to area below the value of current x and y. I don't know how to actually get the right x and y value when the turn is so much that it goes to reduced values of x and y. A concept photo is attached. Anyone knows how to solve this?

Here is my code:

Speed= [1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000,1000] #Incoming Speed
  Angle= [0,0,0,10,0,0,-20,-20,0,35,35,35,35,35,35,35,35] #Incoming Angle
  item = app.findComponent('Ball') #Find component in VC
  delay(0.1)

  newposition = [10,2500,0,90,0,180] #New position array
  x = newposition[0]
  y = newposition[1]
  z = newposition[2]
  w = newposition[3]
  p = newposition[4]
  r = newposition[5]   #wpr is yaw, pitch, roll
  Xold=0
  Yold=2500
  Rold=0     #store x y and r

  for s, a in zip(Speed, Angle):        #get values from array
    delay(1)
    print "(Speed, Angle) ->",(s, a)
    x=s
    y=Yold
    r=a         #just store

    rad=math.radians(a)
    x=math.cos(rad)*s
    y=math.sin(rad)*s           #convert to radians

    Xold=Xold+x
    Yold=Yold+y
    Rold=Rold+r              #add to prev value
    x=Xold
    y=Yold
    r=Rold
    print x,y,r

    mtx = item.PositionMatrix         #get position of BALL
    mtx.P = vcVector.new(x,y,z)   #Position
    mtx.WPR = vcVector.new(w,p,r) #Orientation as yaw,pitch,roll
    item.PositionMatrix = mtx             #store new location
    item.update()
    app.render()

Answer 1

If I understand it correctly, you want to create a steering effect. Inorder to achieve that you will have increase/decrease the value of the angle depending on input. Like so

    public float steeringSensitivity = 2;
    float angle = 0;
    public float speed = 4;
    void Update() {
        float direction = Input.GetAxis ("Horizontal");
        if (direction < 0) {
            angle -= steeringSensitivity * Time.deltaTime;
        } else if(direction > 0) {
            angle += steeringSensitivity * Time.deltaTime;
        }
        Vector3 offset = new Vector3 (speed * Mathf.Cos( angle), speed * Mathf.Sin(angle), 0);
        transform.position += offset * Time.deltaTime;
    }