对于仿人机器人,关节采用挠性驱动方式可吸收振动,减缓冲击,以减小对双足步行的影响。为此,设计并研制FDU-II型挠性驱动单元,与FDU-I型挠性驱动单元相比,具有轻量化、有安全保护、锁紧器使用方便、刚度高、输出精度高等优点;分别进行FDU-II型挠性驱动单元的转速测试、驱动能力测试、大转角频繁往复运动测试、频响测试、机器人步行样本测试等性能测试及用于双足机器人上的步行测试试验;针对等幅值下,频率越高电动机转速越大,机械系统受电动机额定功率所限无法测出其截止频率的问题,提出一种变幅值变频率的频响测试方法,即令电动机转动频率越高时,幅值越小,保证电动机始终不超过额定功率,该方法可有效解决电动机额定功率一定情况下系统截止频率的测试问题;测试结果表明FDU-II型挠性驱动单元在负载力矩12.6 N∙m时,其输出转速达到77.5 º/s,且频响达到6.1 Hz,表明FDU-II比FDU-I有更高带宽及更大功率;步行试验结果表明FDU-II型挠性驱动单元有足够的驱动能力驱动双足机器人髋关节等关节,并实现稳定的双足步行。

For the humanoid robots, the robot joint flexible actuators can absorb external shocks in order to guarantee the stable biped walking. For this, the flexible driving unit FDU-II has been designed and developed, which has the advantages of lighter weight, joint position limit protection, convenient locking mechanism, higher stiffness and higher output accuracy compared to the flexible driving unit FDU-I. The FDU-II is tested by the max speed test, the driving capability test, the big-range reciprocating motion test, the cut-off frequency test, the walking sample contouring test and the biped walking experiments. For the problem that the cut-off frequency of the mechanical system may not be measured because of the motor rated power limitation during the equal amplitude test, an amplitude-adjusting frequency response test method is proposed for the flexible driving unit test, which decreases the motion amplitude when the motion frequency is increased. This method can effectively solve the cut-off frequency testing problem under the given motor rated power condition. The performance test results show that FDU-II can reach the speed of 77.5º/s and the cut-off frequency of 6.1 Hz under the load torque of 12.6 N∙m, and has a higher bandwidth and driving power than the FDU-I. The stable biped walking experiment shows that the FDU-II has enough driving capability for the pitch motion of the biped robot’s hip.