From 7456493b346cee2be496cf67ffc3cc5532e7a6ba Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Mon, 27 May 2013 11:08:07 +1000
Subject: [PATCH] autotest: make rover sim closer to Toms slash

---
 Tools/autotest/pysim/rover.py | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/Tools/autotest/pysim/rover.py b/Tools/autotest/pysim/rover.py
index d3e22e64824..a6312cd4244 100644
--- a/Tools/autotest/pysim/rover.py
+++ b/Tools/autotest/pysim/rover.py
@@ -11,32 +11,35 @@ from rotmat import Vector3, Matrix3
 class Rover(Aircraft):
     '''a simple rover'''
     def __init__(self,
-                 max_speed=13,
-                 max_accel=9,
+                 max_speed=20,
+                 max_accel=30,
                  wheelbase=0.335,
                  wheeltrack=0.296,
                  max_wheel_turn=35,
+                 turning_circle=1.8,
                  skid_steering=False):
         Aircraft.__init__(self)
         self.max_speed = max_speed
         self.max_accel = max_accel
+        self.turning_circle = turning_circle
         self.wheelbase = wheelbase
         self.wheeltrack = wheeltrack
         self.max_wheel_turn = max_wheel_turn
         self.last_time = time.time()
         self.skid_steering = skid_steering
 
-    def turn_circle(self, steering_angle):
-        '''return turning circle (diameter) in meters for steering_angle in degrees
+    def turn_circle(self, steering):
+        '''return turning circle (diameter) in meters for steering angle proportion in degrees
         '''
-        theta = radians(steering_angle)
-        return (self.wheeltrack/2) + (self.wheelbase/sin(theta))
-
-    def yaw_rate(self, steering_angle, speed):
-        '''return yaw rate in degrees/second given steering_angle and speed'''
-        if abs(steering_angle) < 1.0e-6 or abs(speed) < 1.0e-6:
+        if abs(steering) < 1.0e-6:
             return 0
-        d = self.turn_circle(steering_angle)
+        return self.turning_circle * sin(radians(35)) / sin(radians(steering*35))
+
+    def yaw_rate(self, steering, speed):
+        '''return yaw rate in degrees/second given steering_angle and speed'''
+        if abs(steering) < 1.0e-6 or abs(speed) < 1.0e-6:
+            return 0
+        d = self.turn_circle(steering)
         c = pi * d
         t = c / speed
         rate = 360.0 / t
@@ -84,7 +87,7 @@ class Rover(Aircraft):
         speed = velocity_body.x
 
         # yaw rate in degrees/s
-        yaw_rate = self.yaw_rate(self.max_wheel_turn * steering, speed)
+        yaw_rate = self.yaw_rate(steering, speed)
 
         # target speed with current throttle
         target_speed = throttle * self.max_speed