Based on the principle of vehicle-track coupling dynamics, SIMPACK multi-body dynamics software is used to establish a C80 wagon line-coupled multi-body dynamics model with 73 degrees of freedom. And the reasonablenes...Based on the principle of vehicle-track coupling dynamics, SIMPACK multi-body dynamics software is used to establish a C80 wagon line-coupled multi-body dynamics model with 73 degrees of freedom. And the reasonableness of the line-coupled dynamics model is verified by using the maximum residual acceleration, the nonlinear critical speed of the wagon. The experimental results show that the established vehicle line coupling dynamics model meets the requirements of vehicle line coupling dynamics modeling.展开更多
In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also t...In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also taken into account.The longitudinal slip rate is redefined.The grounding pressure distribution of elastic wheels is analyzed and corrected according to speed,temperature and stiffness.Then rolling resistance equation is developed.Finally,simulation is conducted by software CarSim,and the results show that the estimated values are consistent with simulation values,especially at low longitudinal slip rate.The research can help to optimize design of non-pneumatic elastic wheel.展开更多
The complete dynamics model of a four-Mecanum-wheeled robot considering mass eccentricity and friction uncertainty is derived using the Lagrange’s equation. Then based on the dynamics model, a nonlinear stable adapti...The complete dynamics model of a four-Mecanum-wheeled robot considering mass eccentricity and friction uncertainty is derived using the Lagrange’s equation. Then based on the dynamics model, a nonlinear stable adaptive control law is derived using the backstepping method via Lyapunov stability theory. In order to compensate for the model uncertainty, a nonlinear damping term is included in the control law, and the parameter update law with σ-modification is considered for the uncertainty estimation. Computer simulations are conducted to illustrate the suggested control approach.展开更多
为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter...为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter,ARMAX-KF)与速度补偿的拖拉机无前轮传感器转角估计方法。首先,利用Hammerstein非线性系统对拖拉机的转向系统建模,并采用递归最小二乘法(Recursive least squares method,RLS)将其辨识为ARMAX模型;其次,对后轮轴中心接地点速度进行杆臂误差补偿;最后,提出了ARMAX-KF方法,利用卡尔曼滤波器的校正特性,以拖拉机的运动学转角作为观测值,修正ARMAX模型预测的转角速度积分值,从而估计拖拉机的前轮转角。在速度杆臂补偿测量方法试验验证中,补偿后运动学转角平均绝对误差为1.110°,标准差为1.727°,相比补偿前分别减少61.13%和31.55%;在动态转角试验中,ARMAX模型预测的转角速度标准差为2.439(°)/s,相比采用固定传动比方法误差减少56.58%;采用基于ARMAX-KF的前轮转角估计绝对平均误差为0.649°,标准差为0.371°,相比采用固定传动比和卡尔曼滤波器的方法分别减少56.9%和78.82%;在直线导航跟踪试验中,采用基于ARMAX-KF的前轮转角估计标准差为0.649°,本文提出的方法提高了转角估计精度和农机导航作业质量。展开更多
文摘Based on the principle of vehicle-track coupling dynamics, SIMPACK multi-body dynamics software is used to establish a C80 wagon line-coupled multi-body dynamics model with 73 degrees of freedom. And the reasonableness of the line-coupled dynamics model is verified by using the maximum residual acceleration, the nonlinear critical speed of the wagon. The experimental results show that the established vehicle line coupling dynamics model meets the requirements of vehicle line coupling dynamics modeling.
基金supported by the Major Exploration Project of the General Armaments Department of China(NHA13002)the Funding of Jiangsu Innovation Program for Graduate Education+2 种基金the Fundamental Research Funds for the Central Universities of China(CXLX13_145)Jiangsu Province″333 Project″Training Funded Project(BRA2015365)the National Natural Science Foundation of Youth Fund Project(51305175,61503163)
文摘In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also taken into account.The longitudinal slip rate is redefined.The grounding pressure distribution of elastic wheels is analyzed and corrected according to speed,temperature and stiffness.Then rolling resistance equation is developed.Finally,simulation is conducted by software CarSim,and the results show that the estimated values are consistent with simulation values,especially at low longitudinal slip rate.The research can help to optimize design of non-pneumatic elastic wheel.
文摘The complete dynamics model of a four-Mecanum-wheeled robot considering mass eccentricity and friction uncertainty is derived using the Lagrange’s equation. Then based on the dynamics model, a nonlinear stable adaptive control law is derived using the backstepping method via Lyapunov stability theory. In order to compensate for the model uncertainty, a nonlinear damping term is included in the control law, and the parameter update law with σ-modification is considered for the uncertainty estimation. Computer simulations are conducted to illustrate the suggested control approach.
文摘为了解决传统农机导航系统中前轮转角测量传感器不易安装、维护困难以及转角估计不准确等问题,本文提出了一种基于受控自回归滑动平均模型和卡尔曼滤波器的组合模型(Auto-regressive moving average with exogenous input-Kalman filter,ARMAX-KF)与速度补偿的拖拉机无前轮传感器转角估计方法。首先,利用Hammerstein非线性系统对拖拉机的转向系统建模,并采用递归最小二乘法(Recursive least squares method,RLS)将其辨识为ARMAX模型;其次,对后轮轴中心接地点速度进行杆臂误差补偿;最后,提出了ARMAX-KF方法,利用卡尔曼滤波器的校正特性,以拖拉机的运动学转角作为观测值,修正ARMAX模型预测的转角速度积分值,从而估计拖拉机的前轮转角。在速度杆臂补偿测量方法试验验证中,补偿后运动学转角平均绝对误差为1.110°,标准差为1.727°,相比补偿前分别减少61.13%和31.55%;在动态转角试验中,ARMAX模型预测的转角速度标准差为2.439(°)/s,相比采用固定传动比方法误差减少56.58%;采用基于ARMAX-KF的前轮转角估计绝对平均误差为0.649°,标准差为0.371°,相比采用固定传动比和卡尔曼滤波器的方法分别减少56.9%和78.82%;在直线导航跟踪试验中,采用基于ARMAX-KF的前轮转角估计标准差为0.649°,本文提出的方法提高了转角估计精度和农机导航作业质量。
