Chunjie Chen

Catering service robot

Catering service robot working in restaurants is integrated with autonomous mobile, multi-sensor data fusion, and multimodal human computer interaction techniques. Catering service robot can replace or partially take place of the restaurant staffs; it has good marketing effectiveness and potential profitable advantages. In this paper the design of a catering service robot is introduced. Beautiful appearance is used on the robots upper body; the wheeled mobile platform is installed in the bottom of the robot. The robot can be used for customers ordering dishes and offers delivering services in the restaurant with a friendly interactions and self-mobility. The paper analyzes the catering service robot system and describes the framework of the hardware platform and mechanical structure. The software system of the robot includes the motor unit of software module, the realization of autonomous mobile and ordering software module. Finally, the simulation and experiments are carried out.

Flexible design of a wearable lower limb exoskeleton robot

Wearable exoskeleton robot is a kind of humanoid service robot to help the elderly and the patients with walking dysfunction, it is also an effective medical rehabilitation method to help patients who have walking disorders due to central neural system damage. This paper focuses on the flexible mechanism design of wearable lower limb exoskeleton robot. A wearable exoskeleton robot prototype was developed which can assist human walking. This paper analyzes the role of the major joints of walking human by experimental studies based on bionic design methods from human anatomy and bone surgery. We first analyze parameters of joint movements in a gait cycle, then we design a preliminary bionic model, finally we proposed a control strategy including a pair of electric crutches for the exoskeleton robot.

Design and Voluntary Motion Intention Estimation of a Novel Wearable Full-Body Flexible Exoskeleton Robot

The wearable full-body exoskeleton robot developed in this study is one application of mobile cyberphysical system (CPS), which is a complex mobile system integrating mechanics, electronics, computer science, and artificial intelligence. Steel wire was used as the flexible transmission medium and a group of special wire-locking structures was designed. Additionally, we designed passive joints for partial joints of the exoskeleton. Finally, we proposed a novel gait phase recognition method for full-body exoskeletons using only joint angular sensors, plantar pressure sensors, and inclination sensors. The method consists of four procedures. Firstly, we classified the three types of main motion patterns: normal walking on the ground, stair-climbing and stair-descending, and sit-to-stand movement. Secondly, we segregated the experimental data into one gait cycle. Thirdly, we divided one gait cycle into eight gait phases. Finally, we built a gait phase recognition model based on -Nearest Neighbor perception and trained it with the phase-labeled gait data. The experimental result shows that the model has a 98.52% average correct rate of classification of the main motion patterns on the testing set and a 95.32% average correct rate of phase recognition on the testing set. So the exoskeleton robot can achieve human motion intention in real time and coordinate its movement with the wearer.

Deep Spatial-Temporal Model for rehabilitation gait: optimal trajectory generation for knee joint of lower-limb exoskeleton

Purpose The purpose of this paper is to model and predict suitable gait trajectories of lower-limb exoskeleton for wearer during rehabilitation walking. Lower-limb exoskeleton is widely used for assisting walk in rehabilitation field. One key problem for exoskeleton control is to model and predict suitable gait trajectories for wearer. Design/methodology/approach In this paper, the authors propose a Deep Spatial-Temporal Model (DSTM) for generating knee joint trajectory of lower-limb exoskeleton, which first leverages Long-Short Term Memory framework to learn the inherent spatial-temporal correlations of gait features. Findings With DSTM, the pathological knee joint trajectories can be predicted based on subject’s other joints. The energy expenditure is adopted for verifying the effectiveness of new recovery gait pattern by monitoring dynamic heart rate. The experimental results demonstrate that the subjects have less energy expenditure in new recovery gait pattern than in others’ normal gait patterns, which also means the new recovery gait is more suitable for subject. Originality/value Long-Short Term Memory framework is first used for modeling rehabilitation gait, and the deep spatial–temporal relationships between joints of gait data can obtained successfully.

Household Service Robot with Cellphone Interface

In this paper, an efficient and low-cost cellphone-commandable mobile manipulation system is described. Aiming at house and elderly caring, this system can be easily commanded through common cellphone network to efficiently grasp objects in household environment, utilizing several low-cost off-the-shelf devices. Unlike the visual servo technology using high quality vision system with high cost, the household-service robot may not afford to such high quality vision servo system, and thus it is essential to use some of low-cost device. However, it is extremely challenging to have the said vision for precise localization, as well as motion control. To tackle this challenge, we developed a realtime vision system with which a reliable grasping algorithm combining machine vision, robotic kinematics and motor control technology is presented. After the target is captured by the arm camera, the arm camera keeps tracking the target while the arm keeps stretching until the end effector reaches the target. However, i...

Non-binding lower extremity exoskeleton (NextExo) for load-bearing

In this paper, we present a novel non-binding lower extremity exoskeleton (NextExo) for bearing load, where there is no binding point between the NextExo and human. With the innovative structure, the NextExo is able to stand in balance without attaching human, and bear the weights of its own and load completely. This also avoids the damage to operator caused by long-time binding. The NextExo has eight degrees of freedom, all of which are active joints powered by hydraulic actuators. It shadows human motion by one-to-one joints mapping. The man is as the core in the system to keep the NextExo in balance. Meanwhile, the constraint based on Zero Moment Point theory is adopted. The design concept, hardware structure, control scheme and preliminary experiments of NextExo are discussed.

A Household Service Robot with a Cellphone Interface

In this chapter, an efficient and low-cost cellphone-commandable mobile manipulation system is described. Aiming at home use and elderly caring, this system can be easily commanded through a common cellphone network to efficiently grasp objects in a household environment, utilizing several low-cost off-the-shelf devices. Unlike the visual servo technology using a high quality vision system with the associated high cost, the household-service robot would not be able to afford such a high quality vision servo system, and thus it is essential to use some low-cost devices. However, it is extremely challenging to create such a vision system with precise localization, as well as motion control. To tackle this challenge, we developed a real-time vision system with which a reliable grasping algorithm combining machine vision, robotic kinematics and motor control technology is presented. After the target is captured by the arm camera, the arm camera keeps tracking the target while the arm keeps stretching until the end effector reaches the target. However, if the target is not captured by the arm camera, the arm will make a move to help the arm camera capture the target under the guidance of the head camera. This algorithm is implemented on two robot systems: one with a fixed base and another with a mobile base. The results demonstrate the feasibility and efficiency of the algorithm and system we developed, and our study shows the significance of developing a service robot in a modern household environment.

An efficient and low-cost robot grasping system in household environments

In this paper an efficient and low-cost robot grasping system is described. This system efficiently performs grasping tasks of known objects in household environments using just several low-cost devices. For regular visual servo technology that usually applying high-precision but high-cost devices, the target can be localized precisely and the goal arm posture for grasping the target can be calculated accurately, and then the arm can move directly to grasp the target. But for low-cost devices which have very limited performance, it is very difficult to apply this regular technology. In order to overcome this shortage, a new scheme combining machine vision, robotic kinematics and motor control is presented. Using a head camera and an arm camera, the whole grasping problem is split into tow subproblems and then be solved one by one. Our system is tested by performing a representative task in household environments—grasping a coke out of the fridge. The results illustrate that our grasping system accomplishes this kind of grasping task efficiently and successfully.

A MINI-WALKING ROBOT: ARCHITECTURE, ALGORITHM, AND SYSTEM

This paper describes an innovative mini-walking robot with Barbies image. The most special feature of this walking robot is that its total weight and dimensions are expected to be lighter and smaller than other mini-walking robots. And the leg mechanism of the robot can work as smoothly as a humans with only one DOF. The model of this mini-walking robot can be expressed as a walking leg mechanism with a stick. The leg mechanism has been designed to avoid foot interference during walking; we ensure that more than one foot touches the ground all the time. The stick helps the robot move around stably; it supports most of the weight of the robot, and avoids overpressure on legs. Moreover, a dynamic structural model is developed in SimMechanism with toolboxes of Pro/Engineer to analyze parameters, which simulate leg mechanism, solve gait problems, and ensure that the gait of the robot can be more similar to humans. Finally, simulation results and real walking figures are given to verify the feasibility of the proposed mechanism and the real performance of this robot.