# Simulation and Validation of a Steering Control Strategy for Tracked Robots
## 5 Simulation Analysis of Obstacle Avoidance Steering Control
### Center Steering Simulation Analysis  
To investigate how the robot's steering performance is affected by its three steering control strategies, this study utilizes SolidWorks 3D software to construct the robot model. Subsequently, ADAMS(2020) software is employed to impose appropriate constraints on the relevant components of the robot. Figure 10 illustrates the interconnections among the robot's components. The simulation experiments of obstacle avoidance control were completed according to the control requirements by editing the driving function of the robot's obstacle avoidance motion control. In this study, the distance from the side obstacles was 550 mm. Based on the position relationship between the robot and obstacles, two schemes of center steering were set for the robot, in which the robot needed to stop and start several times. Strategy 1 does not consider  
Figure 10: Constraints between robot components. the positional relationship between the robot and obstacles and the length of the robot swing arm; the robot completed the obstacle avoidance steering control by adjusting the motor parameters twice. Although strategy 2 considers the relevant influencing factors, the robot completed the obstacle avoidance steering control by adjusting the motor parameters four times. The simulation process is illustrated in Figure 11. It can be observed that when the robot turned using strategy 1, it collided with obstacles many times, as shown at points A, B, and C in Figure 11a. In this steering process, the influence of the swing arm length on the steering angle was not considered. The reason for the collision of the robot at point A was that the steering angle of the robot was 47.8\({}^{\circ}\), which was greater than the required value of 24.8\({}^{\circ}\). In strategy 2, the robot adjusted the positional relationship between it and the obstacle many times. When the robot drove in a straight line at the initial stage, its maximum steering angle of the robot was 13.2\({}^{\circ}\), which was less than the required 24.8\({}^{\circ}\), and the robot did not collide with the obstacles, as shown in Figure 11b. The driving velocity curves of the two tracks and the skid and slip rates of the tracks are shown in Figure 12. where R and L represent the right and left tracks, respectively, and V and V\({}^{\prime}\) represent the actual traction speed and theoretical traction speed, respectively. Let i represent the skid or slip rate of a track. The numbers 1 and 2 represent the serial numbers of the control schemes. The actual velocity of the track was roughly consistent with the theoretical speed when the robot was driving in a straight line, but the actual velocity of the track was far less than the theoretical velocity when the robot was steering, as shown in Figure 12a-d. During the entire steering process of the robot, the velocities of the left and right tracks changed in the same manner. Changes in the skid and slip rate of the robot under the two strategies are shown in Figure 12e,f, respectively. It can be seen that during the steering process of the robot, the skid and slip rates always changed. The part above the zero axis represents the slip rate and the part below the zero axis represents the skid rate. When the robot started, the slip decreased with an increase in its speed, as shown at point A. The slip rate of the tracked robot was small when the robot was driven in a straight line, as shown at point B.