运用实验法,问卷法,文献资料法,对中国足协曾经作为评判职业足球运动员参赛资格的"YOYO"测试进行研究分析。通过将测试中原有的音乐节奏改进为数字倒数计时来避免运动员在测试中因把握不好节奏犯规的情况,提高运动员的测试成...运用实验法,问卷法,文献资料法,对中国足协曾经作为评判职业足球运动员参赛资格的"YOYO"测试进行研究分析。通过将测试中原有的音乐节奏改进为数字倒数计时来避免运动员在测试中因把握不好节奏犯规的情况,提高运动员的测试成绩,减少运动员体能训练中的"弯路"。提出了应该把"YOYO"测试作为一种辅助手段,重新定位其在中国职业足球体能测试中的位置,更加合理的运用"Y O Y O"测试。展开更多
A general approach for controlling of periodical dynamic systems was presented by taking robotic yoyo as an example. The height of the robot arm when the yoyo arrives at the bottom was chosen as virtual control. The i...A general approach for controlling of periodical dynamic systems was presented by taking robotic yoyo as an example. The height of the robot arm when the yoyo arrives at the bottom was chosen as virtual control. The initial amplitude of yoyo could be mapped to the desired final amplitude by adjusting the virtual control. First,the yoyo motion was formulated into a nonlinear optimal control problem which contained the virtual control. The reference trajectory of robot could be obtained by solving the optimal problem with analytic method or more general numerical approach. Then,both PI and deadbeat control methods were used to control the yoyo system. The simulation results show that the analytic solution of the reference trajectory is identical to the numerical solution,which mutually validates the correctness of the two solution methods. In simulation,the initial amplitude of yoyo is set to be 0.22 m which is 10% higher than the desired final amplitude of 0.2 m. It can be seen that the amplitude achieves the desired value asymptotically in about five periods when using PI control,while it needs only one period with deadbeat control. The reference trajectory of robot is generated by optimizing a certain performance index; therefore,it is globally optimal. This is essentially different from those traditional control methods,in which the reference trajectories are empirically imposed on robot. What's more,by choosing the height of the robot arm when the yoyo arrives at the bottom as the virtual control,the motion of the robot arm may not be out of its stroke limitation. The proposed approach may also be used in the control of other similar periodical dynamic systems.展开更多
文摘运用实验法,问卷法,文献资料法,对中国足协曾经作为评判职业足球运动员参赛资格的"YOYO"测试进行研究分析。通过将测试中原有的音乐节奏改进为数字倒数计时来避免运动员在测试中因把握不好节奏犯规的情况,提高运动员的测试成绩,减少运动员体能训练中的"弯路"。提出了应该把"YOYO"测试作为一种辅助手段,重新定位其在中国职业足球体能测试中的位置,更加合理的运用"Y O Y O"测试。
基金Project(50475025) supported by the National Natural Science Foundation of China
文摘A general approach for controlling of periodical dynamic systems was presented by taking robotic yoyo as an example. The height of the robot arm when the yoyo arrives at the bottom was chosen as virtual control. The initial amplitude of yoyo could be mapped to the desired final amplitude by adjusting the virtual control. First,the yoyo motion was formulated into a nonlinear optimal control problem which contained the virtual control. The reference trajectory of robot could be obtained by solving the optimal problem with analytic method or more general numerical approach. Then,both PI and deadbeat control methods were used to control the yoyo system. The simulation results show that the analytic solution of the reference trajectory is identical to the numerical solution,which mutually validates the correctness of the two solution methods. In simulation,the initial amplitude of yoyo is set to be 0.22 m which is 10% higher than the desired final amplitude of 0.2 m. It can be seen that the amplitude achieves the desired value asymptotically in about five periods when using PI control,while it needs only one period with deadbeat control. The reference trajectory of robot is generated by optimizing a certain performance index; therefore,it is globally optimal. This is essentially different from those traditional control methods,in which the reference trajectories are empirically imposed on robot. What's more,by choosing the height of the robot arm when the yoyo arrives at the bottom as the virtual control,the motion of the robot arm may not be out of its stroke limitation. The proposed approach may also be used in the control of other similar periodical dynamic systems.
