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为了克服被动轮驱动蛇形机器人运动能力弱的缺点,提出了一种新型三连杆主动轮驱动蛇形机器人。该蛇形机器人由多个被动关节连接的串联连杆组成,每个连杆的中心都有一个主动全向轮。全向轮的驱动力只作用于横向,而机器人则沿纵向运动。此外,针对该蛇形机器人具有非完整约束和欠驱动的特点,采用局部坐标系,设计了一种带有防滑功能的运动控制器,使运动和关节角度互不干涉。蛇形机器人蜿蜒爬行实验结果表明,所提出的设计是可行的,且运动控制器有效避免了全向车轮的打滑问题,提高了整个系统的稳定性。 相似文献
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GAO Feng WANG Guofu CUI Ying YANG Xinhong School of Transportation Science & Engineering Beihang University Beijing China 《机械工程学报(英文版)》2011,(4):515-521
The omnidirectional legged vehicle with steering-rails has a specific mechanism feature, and it can be controlled flexibly and accurately in omnidirectional motion. Currently there lacks further research in this area. In this paper, the mechanical characteristics of independent walking control and steering control and its kinematics principle are introduced, and a vehicle has a composite motion mode of parallel link mechanism and steering mechanism is presented. The motion direction control of the proposed vehicle is only dependant on its steering rails, so its motion is simple and effective to control. When the relative motion between the walking and steering is controlled cooperatively, the vehicle can walk perfectly. By controlling the steering rails, the vehicle can walk along arbitrary trajectory on the ground. To achieve a good result of motion control, an equivalent manipulator model needs to be built. In terms of the mechanism feature and the kinematic principle, the simplified manipulator model consists of a rail in stance phase, a rail in swing phase, and an equivalent leg. Considering the ground surface slope during walking, a parameter of inclination angle is added. Based on such a RPP manipulator model, the equations of motion are derived by means of Lagrangian dynamic approach. To verify the dynamic equations, the motion of the manipulator model is simulated based on linear and nonlinear motion planning. With the same model and motion parameters, the dynamic equations can be solved by Matlab and the calculation data can be gained. Compared with the simulation data, the result confirms the manipulator dynamic equations are correct. As a result of such special characteristics of the legged mechanism with steering rails, it has a potential broad application prospects. The derivation of dynamics equation could benefit the motion control of the mechanism. 相似文献
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针对无配重调节器的自行车机器人在低速下不易平衡的问题,以一种前轮驱动自行车机器人为对象,给出其力学模型及在45°车把转角下定车运动的实现方法。通过车轮转弯半径分析推导出后轮角速度、车架航向角速度与前轮驱动速度、车把转角的关系,采用拉格朗日方程建立系统的力学模型;根据部分反馈线性化原理,将包含车架横滚角的欠驱动子系统线性化,设计出自行车机器人45°车把转角下定车运动的平衡控制器。仿真控制结果表明,合理选择控制参数,控制器可以快速地实现自行车机器人在45°车把转角下的定车运动;样机试验结果进一步证明,控制器可以使自行车机器人在不超过驱动电动机的力矩容限下实现45°车把转角下的定车运动。定车运动的实现从理论和试验两个方面证明,自行车机器人在低速下可以不需要配重调节器,仅依靠车把转动和前轮驱动保持稳定平衡。 相似文献
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全方位移动机械手运动控制Ⅰ——建模与控制 总被引:2,自引:1,他引:1
针对一类由轮式驱动全方位移动平台和机械臂所组成的全方位移动机械手,首先通过对机械结构和运动特性的分析,建立一体化运动学模型,并利用拉格朗日力学法建立动力学模型,分析这两种模型的运动性质.然后根据所建立的模型,分别设计轨迹跟踪控制器,并对控制器的稳定性予以证明.在基于动力学模型的轨迹跟踪控制器中,通过结合全方位移动平台的运动学模型和全方位移动机械手的动力学模型,定量地分析移动平台运动状态对机械臂的耦合作用,并在相应的轨迹跟踪控制器中予以补偿.仿真结果不仅显示所提出两种模型的正确性和相应轨迹跟踪控制器的有效性,而且也说明所述方法可以作为一类移动机械手通用的建模和控制方法. 相似文献
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基于阿克曼转向定理,研究电动汽车四轮独立转向系统。利用轮胎"魔术公式"建立二自由度非线性模型,并提出一种基于模糊策略的方法对其质心侧偏角进行控制。整车系统仿真的输入为左前轮车轮转角,其余3个车轮转角由模糊控制决定。质心侧偏角作为模糊控制器的输入,满足阿克曼定理的3个车轮转角作为其输出,由此实现四轮独立转向的控制。仿真研究结果表明所提出算法的有效性。 相似文献
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匹配多套分布式驱动系统可以提升智能汽车的动力学控制能力,但该车在对开坡道起步时仍会存在动力性与方向稳定性难以兼顾问题。提出并验证一种结合主动转向与差动转向的分布式驱动智能汽车双重转向控制方法。根据各驱动轮独立可控的特点,分析对开坡道起步时施加双重转向控制的必要性;根据左右轮驱动力不等导致车辆产生差动转向而偏离直行路线的现象,基于模型预测控制设计出前轮主动转向控制器;结合设计的主动转向控制器与已有的分布式驱动汽车转矩自适应驱动防滑控制器,完成双重转向控制器设计;通过仿真分析和实车道路试验,验证了所设计控制器的控制效果。研究表明:施加双重转向控制,可以使分布式驱动智能汽车尽可能充分利用其自身驱动力和路面可提供的最大附着力;同时,能够根据实时的车身姿态参量和所在位置信息计算出相应的附加转向盘转角,通过主动转向使横向偏移量大幅降低。所提出的基于差动转向与主动转向相结合的双重转向控制,可以全面改善车辆的通过性和方向稳定性。 相似文献
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混合动力汽车在转向过程中易受轮胎垂向载荷、侧向力等因素的影响,为保证其稳定行驶,提出了基于改进相对滑移率的混合动力汽车电子差速控制技术。考虑车辆驾驶时轮胎垂向载荷、侧向力和侧偏角等因素,运用刚体运动原理构建混合动力汽车动力学模型;以车外某点为圆心,通过阿克曼理论计算前轴内外车轮转向角,参考汽车质心速率推算内外车轮转向工况下行驶速度,明确双驱动轮转速;推算内外侧转速和驱动轮距真实转速的耦合关系,将相对滑移率拟作差速控制参数,计算车辆系统性能指标,利用线性二次模型推导差速控制规律,以系统性能指标最小为目标,构建车辆系统最佳差速控制器。结果表明,所提技术能将电子差速滑转率控制在极低水平,降低了车辆的打滑概率,显著提升了车辆驾驶安全性。 相似文献
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城市地下综合管廊内部紧凑,线路长且交叉路段多,采用人工巡检效率低且安全隐患较大,为了实现城市地下管廊实时全方位无盲区探测,提出了一种基于轮毂电机的巡检小车全方位转向机构,包括四轮转向机构、全方位转向机构、转向切换装置以及相关控制系统;并分析了其基本构成及工作原理,在ADAMS中通过运动学分析得到车轮转向曲线,基于MATLAB/Simulink建立驱动系统控制模型。该全转向系统可以有效完成四轮转向、零半径转向、横向移动三种转向功能,比传统四轮巡检小车转向更加灵活,结构简单,具有广阔的应用前景。 相似文献
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Jawad Aslam Shi-Yin Qin Muhammad Adnan Alvi 《Journal of Mechanical Science and Technology》2014,28(8):3301-3310
This research design and implement a robust dynamic feedback controller for a four-wheel skid steering vehicle (SSV) under highspeed cornering motion. First, SSV dynamics are modeled and analyzed to construct the simulation environment and to validate the performance of the proposed algorithm. A robust fuzzy-sliding mode controller is then designed to offset the effect of forces induced by wheel—soil interaction during skidding and ground-level fluctuations. It also eliminates the chattering phenomena encountered with conventional sliding mode control. Given P-3AT mobile robot parameters for trajectory tracking and velocity setting, extensive simulation results demonstrate the effectiveness of the proposed controller. 相似文献
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四轮轮毂电机驱动电动汽车各轮驱动力矩独立可控,可通过控制前轴左右两轮的力矩差实现前轮转向。以四轮轮毂电机驱动智能电动汽车为研究对象,针对线控转向系统执行机构失效时的轨迹跟踪和横摆稳定性协同控制问题,提出一种基于差动转向与直接横摆力矩协同的容错控制方法。该方法采用分层控制架构,上层控制器首先基于时变线性模型预测控制方法求解期望前轮转角和附加横摆力矩,然后考虑转向执行机构建模不确定性以及路面干扰,设计基于滑模变结构控制的前轮转角跟踪控制策略。下层控制器以轮胎负荷率最小化为目标,利用有效集法实现四轮转矩优化分配。最后,分别在高速换道和双移线工况下仿真验证了该控制方法的有效性和实时性。 相似文献
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Yu. N. Zolotukhin K. Yu. Kotov A. S. Maltsev A. A. Nesterov M. N. Filippov A. P. Yan 《Optoelectronics, Instrumentation and Data Processing》2011,47(2):141-150
The influence of the transportation lag and the classical methods of its correction in a control system for a mobile robot
with a differential drive are considered. Such effects as slipping of wheels and surface roughness are demonstrated to restrict
the area of applicability of conventional algorithms of time lag correction. A time lag correction method is proposed, which
is based on analytical extrapolation and extended Kalman filter. Experimental results confirm the efficiency of the approach
proposed. 相似文献
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Kyu Bum Han Hae Young Kim Yoon Su Baek 《Journal of Mechanical Science and Technology》2001,15(8):1097-1107
In this paper, the wall following navigation algorithm of the mobile robot using a mono vision system is described. The key points of the mobile robot navigation system are effective acquisition of the environmental information and fast recognition of the robot position. Also, from this information, the mobile robot should be appropriately controlled to follow a desired path. For the recognition of the relative position and orientation of the robot to the wall, the features of the corridor structure are extracted using the mono vision system, then the relative position, the offset distance and steering angle of the robot from the wall, is derived for a simple corridor geometry. For the alleviation of the computation burden of the image processing, the Kalman filter is used to reduce search region in the image space for line detection. Next, the robot is controlled by this information to follow the desired path. The wall following control scheme by the PD control scheme is composed of two control parts, the approaching control and the orientation control, and each control is performed by steering and forward-driving motion of the robot. To verify the effectiveness of the proposed algorithm, the real time navigation experiments are performed. Through the result of the experiments, the effectiveness and flexibility of the suggested algorithm are verified in comparison with a pure encoder-guided mobile robot navigation system. 相似文献
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以基于麦克纳姆轮的全向移动机器人为研究对象,首先对基于标记点的光学动作捕捉系统的定位原理进行研究,然后对移动机器人的驱动原理和位姿误差进行分析,建立运动学模型和位姿误差模型,通过反演法设计虚拟反馈,并结合李雅普诺夫函数构造出具有全局渐近稳定的轨迹跟踪控制器。接着对测试环境和试验样机进行搭建,将光学动作捕捉系统采集的位姿信息反馈到机器人的控制回路中,最后对直线和圆周轨迹进行跟踪仿真。通过在试验样机上实验验证,总结出利用光学动作捕捉系统对移动机器人采集的定位信息,可令移动机器人拥有良好的轨迹跟踪性能。 相似文献