液压四足机器人机身扰动抑制及实验研究

针对液压四足机器人在运动过程中的机身扰动较大的问题,提出基于运动学和虚拟模型的液压四足机器人机身扰动抑制策略。分析机器人机身扰动产生的机理及其影响,建立四足机器人整机运动学方程,根据机器人实时姿态反馈抑制机身扰动。同时在机器人机身横滚和俯仰自由度上引入弹簧阻尼虚拟元件,通过调整虚拟力的大小控制机身姿态。面向机器人对角小跑步态,对机器人摆动相和支撑相进行足端轨迹规划。通过液压四足机器人平台进行实验验证,实验结果表明,该扰动抑制策略能够根据机器人的机身姿态调整关节角度,机器人机身起伏小,机器人实际运动轨迹与理论运动轨迹接近,验证了所提方法的有效性。     

An experimental characterization of human torso motion

The torso plays an important role in the human-like operation of humanoids. In this paper, a method is proposed to analyze the behavior of the human torso by using inertial and magnetic sensing tools. Experiments are conducted to characterize the motion performance of the human torso during daily routine operations. Furthermore, the forces acting on the human body during these operations are evaluated to design and validate the performance of a humanoid robot.     

Optimization of throwing motion planning for whole-body humanoid mechanism: Sidearm and maximum distance

Throwing is a rapid coordinated movement with high configuration and actuation redundancies. Based on a previous work, this paper advances a numerical framework that optimizes the throwing motions and generates the associated dynamic features for a whole-body humanoid mechanism. To generate physically feasible throwing motions in a fully predictive manner, rigorous dynamic models, such as actuation, biped balance based on Zero-Moment Point (ZMP), and ground reaction loads, are associated with the constraints. The algorithm outputs include the motion, required actuator torques, release parameters, and object projectile. Realistic human-like motions of sidearm and maximum distance throwing are generated as optimized solutions, which demonstrate valid kinematic and dynamic cause-effect relations. The sidearm throw shows better optimality than the overarm throw in terms of actuator torques under the proposed mechanical model; it is characterized by the unique hand trajectory and effective utilization of torso axial rotation. The maximum distance throw is associated with active movement of the arm and torso with larger ranges of motion; it is the release height and speed that increase accordingly.     

基于神经-肌肉架构的仿生并联躯干柔顺控制

模仿动物躯干的构造搭建了六自由度仿生并联躯干。提出一种神经肌肉控制方法,通过控制虚拟肌肉的伸缩使仿生并联躯干在外力冲击下进行柔顺运动。建立了神经运动控制网络,根据非线性振荡器生成的节律信号规划了仿生并联躯干的运动轨迹。运用逆运动学求解了关节转角,按照转角信息控制电机带动仿生并联躯干运动。构建的虚拟肌肉模型在外力作用下驱动躯干关节产生顺应运动。仿真模型和并联躯干实体测试结果表明该方法可有效提高并联躯干的柔顺缓冲性和快速响应性。     

Experimental Characterization of Operation of a Waist-Trunk System with Parallel Manipulators

An extensive research activity has been focused on the upper and lower limbs of humanoid robots. However, due to mechanical design difficulties and complex control of multi-body system, the torso of humanoid robot is somehow a neglected or simplified design part. In this paper, operation performance of a new waist-trunk system as torso for humanoid robots is presented through results of lab experimental tests. The proposed waist-trunk system is composed of two 3 DOFs (degrees of freedom) parallel manipulators, which are connected in a serial chain architecture. A prototype is built by using two prototypes of CaPaMan (Cassino Parallel Manipulator), which are convenient stiff architectures with easy-operation characteristics. Experimental tests are carried out with the aims to imitate lateral-bending and transverse-rotation movements of human torso. Operation performances like displacements, accelerations, and actuation torque are measured for a performance evaluation and design characterization of the used manipulator solution imitating human torso. Experimental test results are illustrated and discussed to show the practical operation feasibility of the proposed architecture and the operation characteristics of the built prototype.     

双足步行机器人整体协调运动规划

通过分析双足步行机器人整体的协调运动,基于D-H法的坐标变换,对步行机器人四肢串联机构进行了重心合成计算.为了增加关节稳定性并提供转动限位,采用改进的"筋"动力耦合关节作为驱动.提出"腿三角"与"臂三角"的概念对多体系统进行了合理有效的简化,并将单摆理论应用于下肢运动,配合上体运动补偿,使上下整体协调运动,给出了两个平面内质心运动的边界条件.最后在三维动力学仿真软件中验证了加入上体补偿运动的合理性.     

外骨骼负重重心自适应凸轮连杆机构设计与性能研究

针对负重型下肢外骨骼机器人存在的问题,提出了一种新的下肢外骨骼机器人重心自适应凸轮连杆机构。具体位置在外骨骼机器人髋关节与靠背板之间,新机构可以满足人体躯干与负重作相反转动,使人体上肢躯干重心前移,抵消负重带来的反向力矩,躯干前倾可增强人体负重行走稳定性。首先分析了新机构工作原理,其次通过重心变化和载荷分配分析验证了新机构有效性,最后对机构仿真验证得出不同负重对应不同躯干的前倾角度,达到重心驱动的效果。MATLAB仿真结果表明：新结构能够满足人体随不同负重而调整对应前倾角度。     

基于中国人体特征的正面碰撞假人的开发策略探讨

采用计算机仿真方法探讨了在现有Hybrid Ⅲ假人基础上通过较少的改变来开发符合中国人体特征的假人的可行性。根据比例缩放方法建立了整体符合中国50百分位人体的假人有限元模型。考虑到中美两国人体最大差异在于四肢,且躯干全部缩放后加工难度较大,故建立了以美国人体特征为基础仅缩放假人四肢和调整部分躯干部件的假人模型,同时,改变假人的材料参数得到了另外一个假人模型。对以上三个假人模型进行碰撞仿真,结果表明,改变假人的材料参数对其碰撞响应的影响很小,而缩放假人外形尺寸对其碰撞响应影响较大,且结果显示缩放假人四肢并调整部分躯干部件的假人与缩放全体段假人的动态响应基本吻合。因此,采用部分缩放的方法来开发中国假人是可行的。     

Assessment of movement distribution in the lumbar spine using the instantaneous axis of rotation

Journal of Mechanical Science and Technology - The position of the torso and the magnitude of exertion are thought to influence the distribution pattern of intervertebral movements within the...     

A three-dimensional active shape model for the detection of anatomical landmarks on the back surface

In this study relations between anatomical landmarks on the dorsal surface of the human torso corresponding to underlying skeletal structures are established. By examining the statistics of the positions of the landmarks in a training set of subjects a point distribution model is derived. Rotations of the pelvis are simulated in order to show that the main mode shapes of variation are consistent with rotations of the pelvis relative to the trunk. The parameters of these mode shapes can therefore be used as independent measures of clinical parameters such as pelvic inclination, pelvic tilt, etc. The point distribution model is further applied to improve reliability and robustness for an automatic and objective detection of the anatomical landmarks on the back surface (active shape model). The results show that it is possible to replace radiographs by surface measurements in order to measure position and orientation of the pelvis, which is particularly valuable in the case of functional examinations that normally involve a large number of radiographs (e.g. to measure the position of the pelvis in a scoliosis).     

Optimal torso design selection for dual 7-DOF robot arm using von Mises stress and workspace analysis

Journal of Mechanical Science and Technology - This paper presents a unique optimal torso design selection technique for the dual seven-degree-of-freedom robot arm. This optimal design enhances the...     

TNO-10型碰撞假人的结构研究

详细阐述了主要用于安全带动态试验的TNO-10型碰撞假人的结构研究。将其分为小腿、头颈部、躯干和大腿等部件,并对每个部件进行了制作过程的讲解,为TNO-10假人的制作提出基础研究参考。     

A numerical study for determining the ideal operating speed for a two-wheeler rider on varying terrain amplitudes

The predominant part of the Indian population generally depends on a two-wheeler for transportation needs. However, very poor road conditions and poor vehicle designs have led to development of pains in the body. The percentage of such incidents involving musculoskeletal pains is alarmingly gaining impetus in the region. Hence, an attempt has been made to analyze and obtain ideal operating conditions of the vehicle for varying terrain amplitudes of 5, 10 and 15 mm, respectively. In this work, a coupled human body and twowheeler is modeled as a lumped parameter system. The composite model is analyzed by computer program (MAT lab) for vertical vibration responses of the different body parts to vertical vibrations inputs that are sinusoidal in nature and applied to wheels of the twowheeler. The numerical analysis is carried out for a Hero Honda splendor vehicle and an average male human body weighing around 80 kilograms. The analysis successfully concludes the torso as the part of the human body that experiences maximum displacement followed by head and thorax for all the terrain amplitudes involved in the study. The study also concludes that the ideal speed of the vehicle to be maintained for the body to experience minimum vibrations is 8 Hz i.e. 49.60 km/hr.     

Design and simulation for a hydraulic actuated quadruped robot

This paper describes the mechanical configuration of a quadruped robot firstly. Each of the four legs consists of three rotary joints. All joints of the robot are actuated by linear hydraulic servo cylinders. Then it deduces the forward and inverse kinematic equations for four legs with D-H transformation matrices. Furthermore, it gives a composite foot trajectory composed of cubic curve and straight line, which greatly reduces the velocity and acceleration fluctuations of the torso along forward and vertical directions. Finally, dynamics cosimulation is given with MSC.ADAMS and MATLAB. The results of co-simulation provide important guidance to mechanism design and parameters preference for the linear hydraulic servo cylinders.     

Design,analysis, and neural control of a bionic parallel mechanism

Frontiers of Mechanical Engineering - Although the torso plays an important role in the movement coordination and versatile locomotion of mammals, the structural design and neuromechanical control...     

Experimental study and model validation of selective spinal cord and brain hypothermia induced by a simple torso-cooling pad

In vivo experiments have been performed to test the effectiveness of a torso-cooling pad to reduce the temperature in the spinal cord and brain in rats. Coolant was circulated through the cooling pad to provide either mild or moderate cooling. Temperatures in the brain tissue, on the head surface, and on the spine and back surfaces were measured. During mild cooling, the temperature on the back surface was 22.82 +/- 2.43 degrees C compared to 29.34 +/- 1.94 degrees C on the spine surface. The temperature on the back surface during moderate cooling was 13.66 +/- 1.28 degrees C compared to 24.12 +/- 5.7 degrees C on the spine surface. Although the temperature in the brain tissue did not drastically deviate from its baseline value during cooling, there was a difference between the rectal and brain temperatures during cooling, which suggests mild hypothermia in the brain tissue. Using experimental data, theoretical models of the rat head and torso were developed to predict the regional temperatures and to validate the rat models. There was good agreement between the theoretical and experimental temperatures in the torso region. Differences between the predicted and measured temperatures in the brain are likely to be the result of imperfect mixing between the cold spinal fluid and the warm cerebrospinal fluid that surrounds the brain.     

Computational studies of 'whiplash' injuries

The term 'whiplash' was initially used to describe injuries to the neck caused by the head being forced backwards during a rear-end collision in cars without head restraints. The addition of head restraints in the 1970s was expected to solve this problem by preventing excessive extension of the neck but experience suggests the problem still exists. This paper reviews available experimental studies of whiplash and uses the data to construct a finite element model which is capable of dynamically simulating whiplash collisions and predicting the forces in all the relevant neck ligaments. For the first time, it is shown that trauma occurs long before the head hits the head restraint as a result of displacement between the head and the torso caused by the head's inertia leading to markedly different acceleration histories. It is concluded that experimental and computational studies must be used together to produce progress in biomechanical studies.     

不平整地面仿人机器人行走控制策略

针对仿人机器人行走于不平整地面会失稳倾倒的现象,提出基于Kane碰撞原理的在线调节控制算法。该调节算法可以实现快速的动力学解算,估算出仿人机器人遇到障碍时地面对腿部的冲击力大小,据此调节仿人机器人的腿部及躯干姿态参数,使机器人成功稳定行走过凸起或凹陷障碍。采用Matlab的Simulink工具,仿真验证了5杆仿人机器人模型基于Kane在线调节控制算法平稳行走过障碍的过程。     

基于C-IASI规程下台车侧面碰撞模拟试验方法研究

为了节约开发成本,减少实车碰撞试验次数,基于中国保险汽车安全指数(China Insurance Automotive Safety Index,C-IASI)中侧面碰撞试验规程,使用带有副台车的加速台车设备,通过主台车复现整车试验假人胸部中间肋骨位置对应车门内钣金Y方向加速度,副台车通过蜂窝铝调节复现车辆非被撞侧B柱Y方向加速度,以此实现台车侧碰模拟试验,并在某车型上进行验证。结果表明:SID-IIs假人躯干伤害与碰撞结果的接近度在90%以上,且仅一次即满足对标要求;基于加速台车和蜂窝铝调节开发的侧面台车试验方法,能够更好代替实车进行侧面约束系统开发试验。     

Multibody approach to dynamic analysis of driver-interactive seatbelt system with motorized retractor

The purpose of this research was to analyze the dynamic behavior of a seatbelt system, focusing on the kinematics of its motorized retractor mechanism as well as its overall performance. The motorized retractor was modeled based on the multibody principle, taking into consideration of the detailed kinematic configuration of the one-way clutch mechanism, which is the critical component of the system. The conditions for fail-safe operation along with the effects of the design parameters of the clutch were studied. It was found that groove length is the most significant design parameter in the engagement and disengagement process. The seatbelt model was setup integrating motorized retractor, flexible webbing and dummy models into a single dynamics system. The validity of the model was confirmed by the good correlation of the simulated and measured webbing forces values obtained from a pre-tensioner detonation test. Using this model, the dynamic performance of the motorized-retractor-driven seatbelt system was evaluated according to a predetermined scenario, and the effectiveness of the retractor’s control of driver posture regardless of the initial torso position was investigated. It was concluded that the seatbelt-driver interaction model can be used as an effective and practical design tool for motorized retractors as well as entire seatbelt systems.