1 INTRODUCTION
In recent years, the control and coordination of multi-robot
[1] has become an interesting research topic in the field of
robot. Mobile multi-robot technology has been widely used
in the fields of industry, military, agriculture, space and
marine development [2]. The robot formation control is an
important part of multi-robot coordination. Faced with
complicated tasks and fickle condition, obviously, it’s not
enough to just depend on the ability of single robot. So it
attracts people’s attention to develop the coordination and
cooperation of multi-robot to finish the task that can never
be done by single robot. The mobile multi-robot formation
requires them as one formation which can arrive at the
target area at the same time, and avoid obstacles in a safe
manner. This kind of group behavior control is the basis to
solve the problem of mobile multi-robot coordination, and
it is of great significance to realize the cooperative missions
of multi-robot in the distributed environment space.
Nowadays, the formation control has been applied in many
fields. For example, in industry field, people control the
mobile multi-robot to carry large objects by certain
formation [3]. In military, multiple autonomous vehicles
have been used to patrol or reconnoiter [4]. In the field of
police, people control the multi-robot to form a cambered
encirclement or to arrest the invaders and so on [5]. AGV
(Automated Guided Vehicles) have been widely used in
practice. In this paper, we do research on multi-robot
formation on the background of AGV.
Normally there are three kinds of approaches for
formation control with applications towards multi-robots:
leader-follower method, behavior-based method and virtual
structure method [6]. In the behavioral approach, the
control action for each robot is derived by a weighted
This work is supported by National Nature Science Foundation of
China under Grant No. 61273068, Nature Science Foundation of Shanghai
under Grant No. 12ZR1412600, and Scientific Research Innovation
Project of Shanghai Education Committee under Grant No. 13YZ084.
* Correspondence Author: LI Xu
average of each desired behavior [4]. This method has clear
formation feedback, and it also realizes the distributed
control, but it does not clearly define the group behavior.
The mathematical analysis cannot be done and the stability
of the formation cannot be guaranteed. In the virtual
structure approach [7], the entire formation is treated as a
single rigid body, and the motion of each agent is derived
from the trajectory of a corresponding point on the
structure. This method can control the motion of the whole
robot formation by defining the rigid body, but it cannot
change the formation when the environment has been
changed, which limits the scope of its application. The
leader-follower method is also named as master-slave mode
[8]. In the group formed by multi-mobile robots, a certain
robot is designated as the leader and the other robots are the
followers. It realizes the formation control through the
followers keeping a certain angle and distance with the
leader, and it can establish different topologies. The
leader-follower method also has a clear definition to the
whole formation, so we can make mathematical analysis to
guarantee the stability of the formation. In this paper, we
put forward a method of robot formation and obstacle
avoidance based on Closed-loop control and Artificial
Potential Field. According to the leader’s location
information [9], we can realize the followers’ trajectory
tracking to the leader and formation control by the
l
−
Closed-loop control, and avoid the obstacles effectively
combined with the Artificial Potential Field method.
In the second part of this paper, we put forward a robot
formation control and obstacle avoidance method, a
tracking control method is in the third part. We change the
problem of followers’ tracking control into a problem of the
control in a system with a certain error. In the fourth part,
we make the simulation verification and finally make a
prospect for the future’s work.
Leader-follower Formation Control and Obstacle Avoidance of Multi-robot Based
on Artificial Potential Field
ZHANG Ying, LI Xu*
College of Information Engineering, Shanghai Maritime University, Shanghai 201306
E-mail: yingzhang@shmtu.edu.cn
Abstract: Leader-Follower formation control of multi-robot was studied in this paper. A formation and obstacle avoidance method wit
multi-robot based on the combination of Closed-loop control and Artificial Potential Field was presented. According to the positio
information of leader, Closed-loop control was introduced to realize the tracking of the follower to the leader, and the formation control
was achieved. The obstacle avoidance could be achieved by Artificial Potential Field method, and the robots can pass the area of obstacle
smoothly. The simulation result shows that the proposed method can achieve the expected control effect, and it can solve this kind o
problems effectively.
Key Words: Multi-robot formation, Leader-follower, Artificial Potential Field, Obstacle avoidance
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2015 IEEE