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Zhang Q.,Beihang University | Ding X.,Beihang University | Xu K.,Beihang University | Xu K.,State Key Laboratory of Robotics and System
Applied Bionics and Biomechanics | Year: 2015

Ruminants live in various parts of land. Similar cloven hooves assist ruminants in adapting to different ground environment during locomotion. This paper analyzes the general terrain adaptability of the feet of ruminants using kinematics of the equivalent mechanism model based on screw theory. Cloven hooves could adjust attitude by changing relative positions between two digits in swing phase. This function helps to choose better landing orientation. Grasping or holding a rock or other object on the ground passively provides extra adhesion force in stance phase. Ruminants could adjust the position of the metacarpophalangeal joint or metatarsophalangeal joint (MTP or MCP) with no relative motion between the tip of feet and the ground, which ensures the adhesion and dexterity in stance phase. These functions are derived from an example from chamois' feet and several assumptions, which are believed to demonstrate the foundation of adaptation of ruminants and ensure a stable and continuous movement. © 2015 Qun Zhang et al. Source

Xiang L.,Shanghai University | Xin L.,Shanghai University | Xin L.,State Key Laboratory of Robotics and System | Xin L.,Shanghai Key Laboratory of Power Station Automation Technology
Journal of Computers | Year: 2011

Speech emotion recognition is an important issue in the development of human-computer interactions. In this paper a series of novel robust features for speech emotion recognition is proposed. Those features, which derived from the Hilbert-Huang transform (HHT) and Teager energy operator (TEO), have the characteristics of multi-resolution, self-adaptability and high precision of distinguish ability. In the experiments, seven status of emotion were selected to be recognized and the highest 85% recognition rate was achieved within the classification accuracy of boredom reached up to 100%. The numerical results indicate that the proposed features are robust and the performance of speech emotion recognition is improved substantially. © 2011 ACADEMY PUBLISHER. Source

Yin X.,Harbin Institute of Technology | Yin X.,University of Alberta | Zhang L.,State Key Laboratory of Robotics and System | Zhang L.,Harbin Institute of Technology | And 3 more authors.
IEEE/ASME Transactions on Mechatronics | Year: 2016

This paper is concerned with a robust control problem of a class of networked systems operated within a multiple communication channels (MCCs) environment. A practical scenario is considered that the active channel in such MCCs for the data communication is switched and the switching is governed by a Markov chain. For each channel, two network-induced imperfections, time delays, and packet dropouts with different characteristics are taken into account. Suppose that the practical plant is subject to energy-bounded disturbance and norm-bounded uncertainties, a robust controller is designed to ensure that the closed-loop system is robustly stable and achieves a disturbance attenuation index against the phenomenon of channel switching. A semi-active suspension system is introduced to illustrate the effectiveness, applicability of the proposed approach, and to demonstrate the advantages of the MCCs scheme within the channel-switching framework. © 2016 IEEE. Source

Liu F.,Bohai University | Gao H.,Bohai University | Qiu J.,State Key Laboratory of Robotics and System | Qiu J.,Harbin Institute of Technology | And 3 more authors.
IEEE Transactions on Industrial Electronics | Year: 2014

This paper investigates the setpoints compensation for a class of complex industrial processes. Plants at the device layer are controlled by the local regulation controllers, and a multirate output feedback control approach for setpoints compensation is proposed such that the local plants can reach the dynamically changed setpoints and the given economic objective can also be tracked via certain economic performance index (EPI). First, a sampled-data multivariable output feedback proportional integral (PI) controller is designed to regulate the performance of local plants. Second, the outputs and control inputs of the local plants at the device layer are sampled at operation layer sampling time to form the EPI. Thus, the multirate problem is solved by a lifting method. Third, the static setpoints are generated by real-time optimization and the dynamic setpoints are calculated by the compensator according to the error between the EPI and objective at each operation layer step. Then, a networked case is studied considering unreliable data transmission described by a stochastic packet dropout model. Finally, a rougher flotation process model is employed to demonstrate the effectiveness of the proposed method. © 1982-2012 IEEE. Source

Huang J.,Huazhong University of Science and Technology | Huang J.,State Key Laboratory of Robotics and System | Ding F.,Huazhong University of Science and Technology | Fukuda T.,Nagoya University | Matsuno T.,Okayama University
IEEE Transactions on Control Systems Technology | Year: 2013

Traffic problems such as pollution and congestion are becoming more and more serious in urban areas. A potential solution to these problems is to develop narrow vehicles that occupy less space and have lower emissions. There has been increasing interest in underactuated mechanical systems, i.e., mobile wheeled inverted pendulum (MWIP) models, which are widely used in the field of autonomous robotics and intelligent narrow vehicles. A novel narrow vehicle based on an MWIP and a movable seat, called UW-Car, is investigated in this paper. The dynamic model of the underactuated vehicle system running on flat ground is derived by Lagrange's equation of motion. Based on the dynamic model and terminal sliding mode control method, two terminal sliding mode controllers are designed to control velocity and braking of the UW-Car. The first one is used to control the forward speed to a desired value while keeping the body upright and the seat on some fixed position. The second one is a switching sliding mode controller, composed of three terminal sliding mode controllers that quickly brakes the system according to an optimal braking scheme. All the control algorithms are tested in both Matlab simulation and a UW-Car experiment. The simulation and experimental results demonstrate the efficiency of the model and controllers. © 2013 IEEE. Source

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