Merge pull request #136 from Achllle/iss134_odomzerodiv

Fix #134 for ROS1, add warning

ROS/osr/src/rover.py

@@ -324,7 +324,12 @@ def forward_kinematics(self):
         drive_angular_velocity = (self.curr_velocities['drive_left_middle'] + self.curr_velocities['drive_right_middle']) / 2.
         self.curr_twist.twist.linear.x = drive_angular_velocity * self.wheel_radius
         # now calculate angular velocity from its relation with linear velocity and turning radius
-        self.curr_twist.twist.angular.z = self.curr_twist.twist.linear.x / self.curr_turning_radius
+        try:
+            self.curr_twist.twist.angular.z = self.curr_twist.twist.linear.x / self.curr_turning_radius
+        except ZeroDivisionError:
+            rospy.logwarn_throttle(1, "Current turning radius was calculated as zero which"
+                                   "is an illegal value. Check your wheel calibration."
+            self.curr_twist.twist.angular.z = 0.  # turning in place is currently unsupported
 
 
 if __name__ == '__main__':