Abstract: Significant research interest has recently been attracted to the study of bipedal robots due to the wide variety of their potential applications. In reality, bipedal robots are often required to perform gait transitions to achieve flexible walking. In this paper, we consider the gait transition of a five-link underactuated three-dimensional (3D) bipedal robot, and propose a two-layer control strategy. The strategy consists of a unique, event-based, feedback controller whose feedback gain in each step is updated by an adaptive control law, and a transition controller that guides the robot from the current gait to a neighboring point of the target gait so that the state trajectory can smoothly converge to the target gait. Compared with previous works, the transition controller is parameterized and its control parameters are obtained by solving an optimization problem to guarantee the physical constraints in the transition process. Finally, the effectiveness of the control strategy is illustrated on the underactuated 3D bipedal robot.

欠驱动3D双足机器人步态切换控制策略

[1]Ames AD, 2014. Human-inspired control of bipedal walking robots. IEEE Trans Autom Contr, 59(5):1115-1130.

[2]Ames AD, Galloway K, Sreenath K, et al., 2014. Rapidly exponentially stabilizing control Lyapunov functions and hybrid zero dynamics. IEEE Trans Autom Contr, 59(4):876-891.

[3]Chevallereau C, Grizzle JW, Shih CL, 2009. Asymptotically stable walking of a five-link underactuated 3D bipedal robot. IEEE Trans Rob, 25(1):37-50.

[4]Collins S, Ruina A, Tedrake R, et al., 2005. Efficient bipedal robots based on passive-dynamic walkers. Science, 307(5712):1082-1085.

[5]Da XY, Harib O, Hartley R, et al., 2016. From 2D design of underactuated bipedal gaits to 3D implementation: walking with speed tracking. IEEE Access, 4:3469-3478.

[6]Da XY, Hartley R, Grizzle JW, 2017. Supervised learning for stabilizing underactuated bipedal robot locomotion, with outdoor experiments on the wave field. IEEE Int Conf on Robotics and Automation, p.3476-3483.

[7]Dehghani R, Fattah A, Abedi E, 2015. Cyclic gait planning and control of a five-link biped robot with four actuators during single support and double support phases. Multibody Syst Dynam, 33(4):389-411.

[8]Freidovich LB, Mettin U, Shiriaev AS, et al., 2009. A passive 2-DOF walker: hunting for gaits using virtual holonomic constraints. IEEE Trans Rob, 25(5):1202-1208.

[9]Geng T, 2014. Online regulation of the walking speed of a planar limit cycle walker via model predictive control. IEEE Trans Ind Electron, 61(5):2326-2333.

[10]Gregg RD, Righetti L, 2013. Controlled reduction with unactuated cyclic variables: application to 3D bipedal walking with passive yaw rotation. IEEE Trans Autom Contr, 58(10):2679-2685.

[11]Griffin B, Grizzle J, 2017. Nonholonomic virtual constraints and gait optimization for robust walking control. Int J Rob Res, 36(8):895-922.

[12]Grizzle JW, Abba G, Plestan F, 2001. Asymptotically stable walking for biped robots: analysis via systems with impulse effects. IEEE Trans Autom Contr, 46(1):51-64.

[13]Grizzle JW, Chevallereau C, Sinnet RW, et al., 2014. Models, feedback control, and open problems of 3D bipedal robotic walking. Automatica, 50(8):1955-1988.

[14]Hamed KA, Grizzle JW, 2014. Event-based stabilization of periodic orbits for underactuated 3D bipedal robots with left-right symmetry. IEEE Trans Rob, 30(2):365-381.

[15]Hamed KA, Buss BG, Grizzle JW, 2016. Exponentially stabilizing continuous-time controllers for periodic orbits of hybrid systems: application to bipedal locomotion with ground height variations. Int J Rob Res, 35(8):977-999.

[16]Hirose M, Ogawa K, 2007. Honda humanoid robots development. Phil Trans R Soc A, 365(1850):11-19.

[17]Hobbelen DGE, Wisse M, 2008. Controlling the walking speed in limit cycle walking. Int J Rob Res, 27(9):989-1005.

[18]Hu Y, Yan GF, Lin ZY, 2011. Feedback control of planar biped robot with regulable step length and walking speed. IEEE Trans Rob, 27(1):162-169.

[19]Kaneko K, Kanehiro F, Morisawa M, et al., 2011. Humanoid robot HRP-4—-humanoid robotics platform with lightweight and slim body. IEEE/RSJ Int Conf on Intelligent Robots and Systems, p.4400-4407.

[20]Kaneko K, Morisawa M, Kajita S, et al., 2015. Humanoid robot HRP-2Kai–-improvement of HRP-2 towards disaster response tasks. Proc 15$^textth$ Int Conf on Humanoid Robots, p.132-139.

[21]Li C, Xiong R, Zhu QG, et al., 2015. Push recovery for the standing under-actuated bipedal robot using the hip strategy. Front Inform Technol Electron Eng, 16(7):579-593.

[22]Montano O, Orlov Y, Aoustin Y, et al., 2017. Orbital stabilization of an underactuated bipedal gait via nonlinear H_∞-control using measurement feedback. Auton Rob, 41(6):1277-1295.

[23]Moon JS, Stipanovic DM, Spong MW, 2016. Gait generation and stabilization for nearly passive dynamic walking using auto-distributed impulses. Asian J Contr, 18(4):1343-1358.

[24]Nguyen Q, Agrawal A, Da XY, 2017. Dynamic walking on randomly-varying discrete terrain with one-step preview. In: Robotics: Science and Systems. Cambridge, MA, USA.

[25]Park IW, Kim JY, Lee J, et al., 2007. Mechanical design of the humanoid robot platform, HUBO. Adv Rob, 21(11):1305-1322.

[26]Shih CL, Grizzle J, Chevallereau C, 2012. From stable walking to steering of a 3D bipedal robot with passive point feet. Robotica, 30(7):1119-1130.

[27]Sreenath K, Park HW, Poulakakis I, et al., 2013. Embedding active force control within the compliant hybrid zero dynamics to achieve stable, fast running on MABEL. Int J Rob Res, 32(3):324-345.

[28]Tang C, Yan GF, Lin ZY, et al., 2015. Stable walking of 3D compass-like biped robot with underactuated ankles using discrete transverse linearization. Trans Inst Meas Contr, 37(9):1074-1083.

[29]Vukobratović M, Borovac B, 2004. Zero-moment point—thirty five years of its life. Int J Humanoid Rob, 1(1):157-173.

[30]Westervelt ER, Grizzle JW, Chevallereau C, et al., 2007. Feedback Control of Dynamic Bipedal Robot Locomotion. CRC Press, Boca Raton, USA.

[31]Yanco HA, Norton A, Ober W, et al., 2015. Analysis of human-robot interaction at the DARPA robotics challenge trials. J Field Rob, 32(3):420-444.

[32]Yang T, Westervelt E, Serrani A, et al., 2009. A framework for the control of stable aperiodic walking in underactuated planar bipeds. Auton Rob, 27(3):277-290.

[33]Yi Y, Lin ZY, 2015. Stability and agility: biped running over varied and unknown terrain. Front Inform Technol Electron Eng, 16(4):283-292.

[34]Yi Y, Lin ZY, Yan GF, 2014. Variable speed running on kneed biped robot with underactuation degree two. Int J Humanoid Rob, 11(2):1450015.