ZJUDancer Team Description Paper
Li Shen, Xiong Rong, Li Jian
State Key Lab. of Industrial Control Technology, Zhejiang University, Hangzhou, China
Abstract This document describes the RoboCup Humanoid League team ZJUDancer from Zhejiang University, China, as required by the qualification procedure for the competition to be held in Mexico City, in June 2012. Full details of our robots including mechanical design, electrical design, sensors and software design are described. With the improved robots, we hope we could get a much better result in 2012.
1 Introduction
The robots developed by ZJUDancer for RoboCup 2012 are fully autonomous humanoid robots which play different parts as a team in the football game. During the past few years, we won the champions of RoboCup China Open 2007, 2009 ,2010 and 2011, and advanced to quarter-finals in Robocup 2009 Graz , Robocup 2010 Singapore and Robocup 2011 Istanbul. This year, lots of efforts has been made to improve our robot system. The team members of ZJUDancer are familiar with the rule of the game and have the ability to serve as referee. Figure. 1 shows our robot.
Table. 1 shows the general specifications of our robots. Three players from ZJUDancer named Wukong, Bajie and Shaseng are fully autonomous humanoid soccer robots. Each robot is fixed to the size and weight limitations of the competition and connected by wireless networks. Referee's directions could be sent to the robot through the network. More details will be introduced in the following sections.
Table 1. General Specifications of the robot
| ZJUDancer |
|---|
| 20 |
| 58cm |
| 35cm |
| 4kg |
2 Mechanical Specifications
The robot from ZJUDancer has 2 legs, 2 arms, 1 trunk and 1 head. The actuators we choose are Dynamixel RX-28 and RX-64. Each robot is driven by 20 servo motors: 6 per leg, 3 in each arm and 2 in the head. The six leg-servos allow for flexible leg movements. Three orthogonal servos constitute the 3-DOF hip joint. Two orthogonal servos form the 2-DOF ankle joint. One servo drives the knee joint. The motor distribution is different but the DOF is the same. Table. 2 shows the details. The robot's mechanical sketch could be seen in Figure. 1(b).
Table 2. Motor types and Distributions of DOF
| Part | Rotation Axis | Actuator |
|---|---|---|
| Neck | Yaw, Pitch | RX-28, RX-28 |
| Shoulder | Roll, Pitch | RX-28, RX-28 |
| Arm | Pitch | RX-28 |
| Hip | Roll, Yaw | RX-64, RX-28 |
| Knee | Pitch, Pitch | RX-64, RX-64 |
| Ankle | Pitch, Roll | RX-64, RX-64 |
| Total DOF | 20 |
3 Electrical Specifications
Our electrical controllers are the motor controller and the camera controller, specifications of which could be seen in Table.3. The camera controller works as the main controller processing image identification, location, strategies selection and communications. The movement and balance maintaining are implemented by the motor controller which executes the movement direction from the main controller. The total electrical architecture could be seen in Figure.2.
Table 3. Electrical Architecture of our robot
| Camera Controller | Motor Controller | |
|---|---|---|
| CPU | Intel Atom Z530 | ATMEL Mega128 |
| FLASH | 4GB | 128KB |
| RAM | 1GB | 64KB |
| OS | Linux | None |
4 Sensor Specifications
There are 4 types of sensors equipped on our robot, which are image sensors, gyroscopes, accelerometers, and potentiometers.
- - Image sensor. We upgrade our camera from Philips SPC900NC to Philips SPC1000NC, which has a more wide view and help improve the efficiency of perception.
- - Gyroscopes. Gyroscopes are equipped in the chest of our humanoid robot. It returns the angular velocity for the trunk of humanoid robot and helps to keep the balance of humanoid robot.
- - Accelerometers. This sensor detects the gravity vector when the robot is static. The main applications of this sensor is that it could be used to recognize whether humanoid robot is standing or lying down. The autonomously getting up from tipping over is depend on this sensor. On the other hand, the dynamic attitude estimate from the fusion of gyros and accelerometers is under research.
- - Potentiometer. This sensor detects the rotation angle of the actuator. With this sensor, the robot recognizes the current angular position of the joint. This sensor is controlled by actuator controller.
5 Software Architecture
The software architecture could also be seen in Figure.3. Each robot works as an independent agent connected by team messages. The team messages could help to update the world model in each robot. We start our software design from image processing. Segmentation and identification help us distinguish each object on the playground. Localization is a complicated fusion of localization of fixed objects and robot locomotion.
6 Conclusion
In this paper, we present the specifications of our robot that has two controllers and 20 DOFs. ZJUDancer has made a great progress in both hardware and software during the last year and looks forward to making a new breakthrough in RoboCup 2012. We'd like to share our experience and have a good match with all the teams.
References
- Tang Qing: ZJUDancer Team Description Paper (2011)
- Du Xinfeng: Fast recognition and precise localization of humanoid soccer robot vision system. Journal of Zhejiang University (Engineering Science). Vol. 43 No. 11, 1975–1981 (2009)
- User's Manual for Dynamixel RX-28 (2007)
- User's Manual for Dynamixel RX-64 (2006)
- W.Richard Stevens, Stephen A. Rago: Advanced Programming in the UNIX Environment. 2nd Edition. (2005)