自控速度的平滑滚动引导式和RSVP的文本阅读

考察了在自控速度条件下 ,显示窗口、起始速度和文本显示方式等因素对视频显示终端 (videodisplayter minals,VDT)汉语文本阅读工效的影响。结果发现 :(1)在阅读正确率上 ,VDT文本的平滑滚动引导式优于快速系列视觉呈现 (rapidserialvisualpresentation ,RSVP)方式 ;(2 )阅读速度和阅读理解成绩相互代偿 ,若注重理解正确率 ,宜采用 15 0字 /分的起始速度 ;若兼顾阅读速度 ,宜采用 75 0字 /分的起始速度 ;(3)起始速度、显示窗口和文本显示方式三者共同影响了阅读绩效 ;(4 )机控速度方式的阅读效率优于自控速度方式。

速度自控式输气管道内检测器移动载体的研究

文章围绕长距离天然气输送管道的在线内检测器速度控制方面开展相关的技术研究,课题组在大量研究基础上提出一种具有调速响应迅速、无能耗、可靠性高、速度波动范围小等特点的机器人,具有很好的实用推广应用价值。

New Adaptive Cruise Control Method

A new adaptive cruise control (ACC) method based on the desired safety headway distance is investigated for improving the vehicle traffic safety at high speed by regulating the additional throttle opening and braking torque of driving wheels only. The selection of headway distance sensors, the determination of desired safety headway distance and desired deceleration are elaborated. The ACC flowchart and simulation, as well as signal misinformation and its resolutions are described. The simulation proves that the new ACC method is simpler and feasible. The new method is easily integrated ACC with ABS/ASR to form an organic ABS/ASR/ACC system.

Acid-pickling plates and strips speed control system by microwave heating based on self-adaptive fuzzy PID algorithm

Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful in overcoming non-linear dynamic behavior, uncertain and time-varying parameters, un-modeled dynamics, and couples between the automatic turbulence control (ATC) and the automatic acid temperature control (AATC) with varying parameters during the operation process. The quasi-cascade control system of inner and outer loop self-adaptive fuzzy PID controller was built, which could effectively control the pickling speed of plates and strips. The simulated results and real application indicate that the plates and strips acid pickling speed control system has good performances of adaptively tracking the parameter variations and anti-disturbances, which ensures the match of acid pickling temperature and turbulence of flowing with acid pickling speed, improving the surface quality of plates and strips acid pickling, and energy efficiency.

Application of linear active disturbance rejection control for photoelectric tracking system

Dynamic characteristics and tracking precision are studied in the photoelectric tracking system and a linear active disturbance rejection control( LADRC) scheme is proposed for position loop. A current and speed controller is designed by a transfer function model,which is obtained by adaptive differential evolution. Model error,friction and nonlinear factor existing in position loop are treated as ‘disturbance',which is estimated and compensated by generalized proportional integral( GPI)observer. Comparative results are provided to demonstrate the remarkable performance of the proposed method. It turns out that the proposed scheme is successful and has superior features,such as quick dynamic response,low overshoot and high tracking precision. Furthermore,with the proposed method,friction is suppressed effectively.

Mathematical Modelling of a Two Degree of Freedom Platform Using Accelerometers and Gyro Sensors

This paper demonstrates the assembly of a servo-controlled platform with two degrees of freedom, empirical methods and a developed closed-loop control found in the system mathematical model. This control aims to stabilize and hold small objects on the platform. We parsed the step response in X and Y axes, hence we found the first and second-order models for each one. We did some further analyses to decide which one would better represent the behavior of the system. The MATLAB software provided step response for the model empirically obtained and latter compared it to experimental data acquired in the trials. Accelerometers and gyro sensors from the MPU-6050 sensor measured the angular position of platform on X and Y axes. In order to improve measurements accuracy and eliminate noise effects, we implemented the complementary filter to the firmware system. We used Arduino to control servomotors through PWM pulses and perform data acquisition.

High speed interpolation for micro-line trajectory and adaptive real-time look-ahead scheme in CNC machining

CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.For the consecutive micro-line segments interpolation,the velocities at the junction of two segments are the bottlenecks for the machining efficiency.This paper proposes a multi-period turning method to improve the feedrate at the junctions using the linear acceleration and deceleration mode,which utilizes the maximal acceleration capabilities of the NC machine while satisfying the machining precision.A new and more efficient look-ahead method and a feedrate override method are also proposed to boast the global machining speed.The proposed algorithm has been implemented on Blue Sky NC System,and experimented in real material manufacturing.Compared with several existing algorithms,the current algorithm can improve the manufacturing time ranging from 50% to 180%,depending on the machining parameters,and also results in better machining quality.In addition,the algorithm also satisfies the need of real-time interpolation.