This work presents the coordinated motion control and obstacle-crossing problem for the four wheel-leg independent motor-driven robotic systems via a model predictive control (MPC) approach based on an event-triggering mechanism. The modeling of a wheel-leg robotic control system with a dynamic supporting polygon is organized. The system dynamic model is 3 degrees of freedom (DOF) ignoring the pitch, roll and vertical motions. The single wheel dynamic is analyzed considering the characteristics of motor-driven and the Burckhardt nonlinear tire model. As a result, an over-actuated predictive model is proposed with the motor torques as inputs and the system states as outputs. As the supporting polygon is only adjusted at certain conditions, an event-based triggering mechanism is designed to save hardware resources and energy. The MPC controller is evaluated on a virtual prototype as well as a physical prototype. The simulation results guide the parameter tuning for the controller implementation in the physical prototype. The experimental results on these two prototypes verify the efficiency of the proposed approach.
KYON: Semi-Modular Wheel-Legged Quadruped With Agile Bimanual Capability
Humanoids and Human Centered Mechatronics, Fondazione Istituto Italiano di Tecnologia（人机一体化机械系统，意大利理工研究院）；Advanced Robotics Facility, Fondazione Istituto Italiano di Tecnologia（先进机器人设施，意大利理工研究院）
X2-N: A Transformable Wheel-legged Humanoid Robot with Dual-mode Locomotion and Manipulation
Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology（香港理工大学电子与计算机工程系）；X-lab Department, Agibot Innovation Company（阿吉博创新公司X实验室）
Leg-Arm Coordinated Operation for Curtain Wall Installation
Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences（中国科学院深圳先进技术研究院）；Shenzhen University of Advanced Technology and University of Chinese Academy of Sciences（深圳先进技术大学和中国科学院大学）
Whole-Body Control With Terrain Estimation of A 6-DoF Wheeled Bipedal Robot
School of Intelligent Systems Engineering, Sun Yat-sen University（中山大学智能系统工程学院）；Direct Drive Technology Limited（直接驱动技术有限公司）；Suzhou Nuclear Power Research Institute Co., Ltd（苏州核电研究所有限公司）
Modeling and Control of a Hybrid Wheeled Jumping Robot
School of Informatics, The University of Edinburgh（爱丁堡大学信息学院）；Shenzhen Institute for Artificial Intelligence and Robotics for Society (AIRS)（深圳市人工智能与机器人研究院）；Oxford Robotics Institute, University of Oxford（牛津大学牛津机器人研究所）
MUJICA: Multi-skill Unified Joint Integration of Control Architecture for Wheeled-Legged Robots
College of Intelligent Robotics and Advanced Manufacturing, Fudan University（智能机器人与先进制造学院，复旦大学）；Power China Huadong Engineering Corporation Limited（中国电力工程顾问集团华东分公司）
Ubiquitous Field Transportation Robots with Robust Wheel-Leg Transformable Modules
Southern University of Science and Technology（南方科技大学）；Carnegie Mellon University（卡内基梅隆大学）；Hong Kong University of Science and Technology（香港科技大学）；National University of Singapore（新加坡国立大学）
Unleashing the Agility of Wheeled-Legged Robots for High-Dynamic Reflexive Obstacle Evasion
School of Mechanical Engineering, Tianjin University（天津大学机械工程学院）；School of Computing, National University of Singapore（新加坡国立大学计算机学院）；Beijing Zhongguancun Academy（北京中关村学院）；DeepRobotics（深睿科技）
Dynamics, stability, and energy efficiency of an energy-recycling rimless wheel with spring-clutch legs
Department of Mechanical Engineering and Robotics, Guangdong Technion-Israel Institute of Technology（广东以色列理工学院机械工程与机器人系）；Faculty of Mechanical Engineering, Technion-Israel Institute of Technology（以色列理工学院机械工程学院）；Department of Applied Electronics, Faculty of Advanced Engineering, Tokyo University of Science（东京理科大学先进工学部应用电子系）
Arm-Constrained Curriculum Learning for Loco-Manipulation of the Wheel-Legged Robot
The Hong Kong University of Science and Technology (Guangzhou)（香港科技大学（广州））；Institute for AI Industry Research (AIR), Tsinghua University（清华大学人工智能产业研究院）；Tsinghua University（清华大学）；Harbin Institute of Technology（哈尔滨工业大学）；Xi’an Jiaotong-Liverpool University（西交利物浦大学）
Whole-body Motion Control of an Omnidirectional Wheel-Legged Mobile Manipulator via Contact-Aware Dynamic Optimization
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology（智能制造装备与技术国家重点实验室，机械科学与工程学院，华中科技大学）
Whole-Body Inverse Dynamics MPC for Legged Loco-Manipulation
Department of Mechanical and Process Engineering, ETH Zurich（机械与过程工程系，苏黎世联邦理工学院）；Computational Robotics Lab, Department of Computer Science, ETH Zurich（计算机器人实验室，计算机科学系，苏黎世联邦理工学院）
Learning to Recover: Dynamic Reward Shaping with Wheel-Leg Coordination for Fallen Robots
Humanoids and Human-Centered Mechatronics (HHCM), Istituto Italiano di Tecnologia（人类oids与人本机电系统（HHCM），意大利技术研究所）；Ph.D. Program of National Interest in Robotics and Intelligent Machines (DRIM), University of Genova（机器人与智能机器国家利益博士项目（DRIM），热那亚大学）；Department of Computer Science, University College London（计算机科学系，伦敦大学学院）
Dynamically Extensible and Retractable Robotic Leg Linkages for Multi-task Execution in Search and Rescue Scenarios
Mechanical and Aerospace Engineering Department, University of California, San Diego（加州大学圣地亚哥分校机械与航空航天工程系）；Electrical and Computer Engineering Department, University of California, San Diego（加州大学圣地亚哥分校电气与计算机工程系）
Design and Dimensional Optimization of Legged Structures for Construction Robots
Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences（中国科学院深圳先进技术研究院）；School of Transportation and Logistics Engineering, Wuhan University of Technology（武汉理工大学交通运输与物流工程学院）；University of Chinese Academy of Sciences（中国科学院大学）
