DSP在旋转机械位置控制系统中的应用

介绍了基于DSP(TMS320LF2407)的旋转机械位置控制系统的设计。针对TMS320LF2407的特点,叙述了以TMS320LF2407为核心的数字控制硬件系统的构成以及相关外围电路的设计。采用PID控制,并用汇编语言与C语言结合的方法编制了相应的数控软件。实验表明,以TMS320LF2407为核心的数字控制硬件系统不仅能够满足系统的要求,而且易于实现各种先进的控制方案。

调整CA-1500加样针的机械位置

CA- 15 0 0血凝仪是日本产的 Sysmex系列之一。在仪器的使用过程中 (如仪器搬运 ) ,仪器的加样针有时会发生位移 ,这样一来 ,在工作中就有可能发生加样针伸到试管或试剂杯的边上而造成毁针的事故 ,损失是相当大的。一般来说 ,发现工作中加样针位置不正时可以请厂家的工程师来调整 ,但自己也是能调整的。作者介绍了自己如何调整加样针及标本杯 Catcher的走位 ,根据自己的仪器的实际使用情况来进行调整 ,因反应杯的规格在各个厂家是有所不同的 ,Catcher与之不相匹配时 ,在加试剂时很容易发生掉杯子而影响工作。在调整之后 ,就可以放心地使用而不必担心会出现毁针。

数字孪生下的液压缸机械运行位置自动控制

液压缸机械系统非线性特征复杂,机械运行行为特征不明确,位置控制结果存在偏差,对此,该文提出数字孪生下的液压缸机械运行位置自动控制方法。连续检测液压缸机械系统运行状态,构建非线性状态方程,对比实际测量数据与输出数据的差异,选取RBF核函数与支持向量机,机械运行位置变化量,描述机械运行行为特征,建立位置控制目标函数,将最高适应度值对应的位置点自动更新为副本位置点,引入猫群算法求解目标函数,对位置控制目标函数的全局最优解展开更新,实现液压缸机械运行位置自动控制。实验结果表明,所提方法应用后,位移检测曲线与实际位移曲线之间的偏差较小,且在恒负载工况下和变负载工况下,位移稳态误差均较小,说明其机械运行位置自动控制结果精度高、控制效率高、控制精度高。

转位机械臂捕获初始条件分析

对接环的推出精度、主被动环的间隙是转位机械臂捕获锥捕获初始条件偏差的主要来源;二者与捕获初始条件偏差的关系由转臂的尺寸、舱体的尺寸决定;用矢量分析的方法,建立了从转位机械臂到节点舱接纳锥空间位置姿态关系的解析数学模型,应用Adams和Matlab软件对捕获初始条件范围进行了计算和分析,为接纳锥尺寸设计及机械臂方案提供了依据。

TSG18受电弓降弓位置指示器故障原因分析及整改措施

针对TSG18地铁受电弓降弓位置指示器放电的故障现象,文章从降弓位置指示器的工作原理、绝缘子的电气参数以及受电弓使用环境的空气质量等方面分析了故障原因,并提出了相应的整改措施。

关于某型装备发控通道机电融合检测装置的设计与实现

通过多年的保障实践,从系统检测角度,把某型装备发控通道、机械位置及对接可靠性进行了有机融合,设计制作机电一体化测试工装,为现役潜艇某武器系统通道的性能检测提供有力的工具,提高装备的稳定性和可靠性,已多次应用于维修保障实践,军事经济效益明显。

A New Type of Continuously Variable Displacement Mechanism Used for Hydraulic Motors

A continuously variable displacement mechanism, which is composed of a hydraulic control valve with mechanical-positional feedback to camshaft, was designed for changing the displacement of traditional camshaft connecting-rod low speed high torque (LSHT) hydraulic motor continuously. The new type of continuously variable displacement mechanism is simple and easy to be made. The structure and principle of a continuously variable displacement mechanism was introduced. The mathematic model of the continuously variable displacement mechanism was set up and its static and dynamic characteristics were analyzed with the help of computer simulation. It can be seen that the cam ring on camshaft of the traditional LSHT hydraulic motor can stop at any position between minimum and maximum eccentricity, according to an input fluid pressure signal. And it can also stay anywhere stably through self-adjusting. Besides, it can work stabilized when load impact or oil leakage exists.

Speed-assigned Position Tracking Control of SRM With Adaptive Backstepping Control

A novel speed-assigned method is applied to the position tracking control of switched reluctance motor(SRM).A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective.

Inverse kinematics of a heavy duty manipulator with 6-DOF based on dual quaternion

An iterative method is introduced successfully to solve the inverse kinematics of a 6-DOF manipulator of a tunnel drilling rig based on dual quaternion, which is difficult to get the solution by Denavit-Hartenberg(D-H) based methods. By the intuitive expression of dual quaternion to the orientation of rigid body, the coordinate frames assigned to each joint are established all in the same orientation, which does not need to use the D-H procedure. The compact and simple form of kinematic equations, consisting of position equations and orientation equations, is also the consequence of dual quaternion calculations. The iterative process is basically of two steps which are related to solving the position equations and orientation equations correspondingly. First, assume an initial value of the iterative variable; then, the position equations can be solved because of the reduced number of unknown variables in the position equations and the orientation equations can be solved by applying the solution from the position equations, which obtains an updated value for the iterative variable; finally, repeat the procedure by using the updated iterative variable to the position equations till the prescribed accuracy is obtained. The method proposed has a clear geometric meaning, and the algorithm is simple and direct. Simulation for 100 poses of the end frame shows that the average running time of inverse kinematics calculation for each demanded pose of end-effector is 7.2 ms on an ordinary laptop, which is good enough for practical use. The iteration counts 2-4 cycles generally, which is a quick convergence. The method proposed here has been successfully used in the project of automating a hydraulic rig.

Global optimization of manipulator base placement by means of rapidly-exploring random tree

Due to the interrelationship between the base placement of the manipulator and its operation object,it is significant to analyze the accessibility and workspace of manipulators for the optimization of their base location.A new method is presented to optimize the base placement of manipulators through motion planning optimization and location optimization in the feasible area for manipulators.Firstly,research problems and contents are outlined.And then the feasible area for the manipulator base installation is discussed.Next,index depended on the joint movements and used to evaluate the kinematic performance of manipulators is defined.Although the mentioned indices in last section are regarded as the cost function of the latter,rapidly-exploring random tree(RRT) and rapidly-exploring random tree*(RRT*) algorithms are analyzed.And then,the proposed optimization method of manipulator base placement is studied by means of simulation research based on kinematic performance criteria.Finally,the conclusions could be proved effective from the simulation results.

Relationship of Milk Line Position with Grain Weight and Mechanized Harvest of Summer Corn

To investigate the relationship of milk line position with grain weight and mechanized harvest of summer corn in Huang-Huai-Hai Region, 8 varieties （A, B, C, D, E, F, G, H） with large planting areas were selected to measure the grain filling rate, 100-grain weight, water content and milk line position, and the correlation was analyzed. Results showed that when the milk line position was 90%, the grain filling of all the 8 varieties finished and 100-grain weight reached the highest value, which was 43.02 g. The grain filling time was in positive correlation with 100-grain weight. However, when the milk line position completely disappeared, the 100-grain weight was reduced by 8.66% at most. There was no significant difference during the periods of grain weight rising, but in the periods of grain weight falling, the traits of D, E, H were significantly different with the other varieties, and water loss rate of C and A showed significant difference with the other six varieties. The water content of grain was negatively correlated with milk line position. When the milk line percentage was 90% , the grain water content was less than 30% . The key factor influencing the mechanized harvest of summer corn is harvesting time, rather than the varieties. Moreover, milk-line position of 90% is the best time for harvest; if the harvest is too late, the yield will be reduced with varying degrees.

Robowler:Design and development of a cricket bowling machine ensuring ball seam position

The art of cricket bowling is complex and arduous owing to the run-up and ball release time energy requirement to achieve speed and variations. Therefore, human bowlers cannot bowl for extended periods and numerous mechanical bowling machines have been built to help batsmen improve their skills during practice sessions. However, most of these existing machines are designed for spherical balls ignoring the distinguishing physical feature of a cricket ball: the raised equatorial seam, which makes it less of a sphere. The bowlers are known to often benefit from this seam in their pursuit to taking the batsmen's wicket by imparting swing, spin and bounce variations along-with other bowling variables. This lack of the seam consideration creates a void between human and mechanical bowling. In this work, we present design and development of an automatic bowling machine termed as ROBOWLER to make mechanical bowling more realistic. This machine ensures ball seam position as well as fulfills other constraints. Ball pitching and seam position accuracy results underscore the suitability of this design to enhance the capabilities of mechanical bowling.

Magnification Ratio of Mechanical Displacement Amplifier in Sensing Device

In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution and accuracy than conventional extensometers.However,the relation between the magnification ratio and the structure size of the displacement amplifier is a bottleneck of sensing device design.Addressing this,the magnification ratio of a mechanical displacement amplifier is analytically derived based on its geometry structure.Six prototypes of the displacement amplifier made in propathene are manufactured,and an experimental system is set up to validate the accuracy of the established magnification ratio equation.Theoretical magnification ratios and experimental magnification ratios are compared and agree well,which verifies that the proposed equation is reliable.This analytical equation provides an effective design method for bridge-shaped mechanical displacement amplifiers with an expected magnification ratio.