A scheme of improving performance of hydrostatic journal support was presented, that is, control journal support pose by controlling flow of four controllable chambers and Coupling various oil film thickness, to assur...
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ISBN:
(纸本)9783037850046
A scheme of improving performance of hydrostatic journal support was presented, that is, control journal support pose by controlling flow of four controllable chambers and Coupling various oil film thickness, to assure journal support expected pose;Chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal results of journal support. The mathematical model of the controllable chambers flow, servo variable mechanism and controller were built;the pose control model was established, which contain the kinematics positive and negative solution and control strategy of hydraulic cylinder position feedback;hardware-in-loop simulation experiment was carried on the electro hydraulic servo test bench by mean of the non-linear relation of film thickness and the hydraulic cylinder displacement. simulation and hardware-in-loop simulation experiment results show that the controllable journal support exhibit high oil film rigidity can stably and quickly track the expected goal and can be broadly applied in high precision heavy horizontal machine tool.
Dynamic variation and stabilization of color temperature according to user preferences, using multichip Red-Green-Blue LEDs, is a challenging task. Color point can vary due to variation in junction temperature caused ...
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ISBN:
(纸本)9789811055201;9789811055195
Dynamic variation and stabilization of color temperature according to user preferences, using multichip Red-Green-Blue LEDs, is a challenging task. Color point can vary due to variation in junction temperature caused due to self-heating, variation in ambient temperature, and device aging. In this paper, we present a closed-loop system that can tune and control the color points from 2700 to 6500 K from the variations of ambient temperature. Open-loop results obtained using forward voltage technique clearly show the effect of temperature on forward voltage, total flux, tristimulus values, color point, and peak wavelength. The effect of PWM dimming factor on tristimulus values is also studied. Nonuniform decay rates of Red-Green-Blue LEDs demand the design of separate control loops. Thus, a cost-effective hardware-in-loop simulation system with individual color control, compensating the temperature by instantly detecting the diode forward voltage with minimum number of components, is designed and validated.
Due to the separation of the radar transmitter and receiver, the channel mismatch, the time and phase synchronization error between synthetic aperture radar (SAR) central electronic equipments (CEE) is the key problem...
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ISBN:
(纸本)9781457710056
Due to the separation of the radar transmitter and receiver, the channel mismatch, the time and phase synchronization error between synthetic aperture radar (SAR) central electronic equipments (CEE) is the key problems of spaceborne distributed SAR system compared with the traditional single-satellite double pass interferometric SAR (InSAR) system, which has to be considered in the SAR system design, index allocation, integration and testing, verification and validation. A hardware-in-loop simulation and evaluation approach is presented for the influence analysis of CEE payload on the InSAR performance. The hardware-in-loop simulation system includes the master and slave CEE payloads, the time and phase synchronization prototypes, the on-board computer simulator, the SAR target echo signal simulator (TESS) and other auxiliary equipments. For obtaining the influence of the error source on InSAR performance, a hardware-in-loop simulation and evaluation approach based on different hardware configuration is adopted. The experiment results validate the theoretical analysis and computer-based simulation results, and show the feasibility of the time and phase synchronization scheme, which is meaningful for the implementation of the spaceborne distributed SAR system.
This paper presents the improved control strategy with optimal switching scheme to improve the bidirectional converter's power flow control capability and to allow for different modes of operation in hybrid AC/DC ...
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This paper presents the improved control strategy with optimal switching scheme to improve the bidirectional converter's power flow control capability and to allow for different modes of operation in hybrid AC/DC microgrid. Also, this improved control strategy eliminates the need of PI controller for independent reactive power control. With the improvements in digital controllers, it is possible to implement complex control circuitry easily. The performance of bidirectional converter with improved control strategy is verified first in simulation environment and then on lab scale experimental set-up with the control circuit is implemented using hardware in loop in the real-time digital simulation platform. The simulation and experimental results for all the cases show that the controller is highly capable for power transfer between AC and DC grid with very fast response and also control reactive power without additional PI controller. Also, it maintains the current total harmonic distortion (THD) within standard limits.
hardware-in-loop simulation (HIL) of underwater heat-engine system is more believable than a mathematic simulator. In-depth presentations of a backpressure simulation device, a load pressure simulation device and a ro...
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ISBN:
(纸本)9781424458479
hardware-in-loop simulation (HIL) of underwater heat-engine system is more believable than a mathematic simulator. In-depth presentations of a backpressure simulation device, a load pressure simulation device and a rotating rate controller are given which make up of the HIL of underwater heat-engine system. Section 1 of the full paper establishes and analyzes the mathematical model for such a HIL system. Section 2 synthesizes the closed loop control law of backpressure;the most important result in the mathematical derivation is eq. (13). Section 3 establishes control algorithm of load pressure simulation device as shown in eq. (16). And the dynamic characteristics of the system is modified in section 4. To verify the control law, a HIL experiment on the propulsion system is carried out. Fig. 3 in section 5 gives the experimental ressults. Initial evaluation indicates that the dynamic simulation precision of both the load presuure and rotating controller achieve 1.5%, and backpressure achieves 0.5%. The study provides a necessary theoretical basis for further study of the dynamic control problem for underwater heat-engine system.
This paper presents a variant of the cyclic pursuit strategy that can be used for target tracking applications. Cyclic pursuit has been extensively used in multi-agent systems for a variety of applications. In order t...
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This paper presents a variant of the cyclic pursuit strategy that can be used for target tracking applications. Cyclic pursuit has been extensively used in multi-agent systems for a variety of applications. In order to monitor a target point or to track a slowly moving vehicle, we propose to use a group of non-holonomic vehicles. At equilibrium, the vehicles form a rigid polygonal around the target while encircling it. Necessary conditions for the existence of equilibrium and the stability of equilibrium formations are analysed considering unicycle model of the vehicles. The strategy is then applied to miniature aerial vehicles (MAV) represented by 6-DOF dynamical model. Finally the results are verified in a hardware in-loop simulator in real time, which included all on-board electronics of the MAVs.
Vehicle fuel economy is poor, because the urban traffic is congested, the auto is constantly in the idle condition resulting in the increase of fuel consumption. In order to improve the vehicle fuel economy, the exper...
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Vehicle fuel economy is poor, because the urban traffic is congested, the auto is constantly in the idle condition resulting in the increase of fuel consumption. In order to improve the vehicle fuel economy, the experimental scheme was designed through analyzing the work mechanism of automobile Idling Stop＆start System（ISS）. Engine working conditions were simulated by drive motor, the road resistance was simulated through electromagnetic brake controlled current to achieve the control of braking torque. The models of ISS were established, which consists of drive motor, regenerative braking, braking pedal and road resistant simulation. The test system was verified based on hardware in the loopsimulation test system. The test results show that the models and the experimental scheme are rational and effective. It is a good testing and simulation platform for the further research on energy-saving mechanism and control technology.
In order to test and evaluate the automatic transmission (AT) electronic control system and improve the development efficiency with lower cost, a hardware-in-loop simulation (HILS) platform of AT electronic control sy...
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ISBN:
(纸本)9781509035724
In order to test and evaluate the automatic transmission (AT) electronic control system and improve the development efficiency with lower cost, a hardware-in-loop simulation (HILS) platform of AT electronic control system is built. To simulate the electro-hydraulic proportional control loop and test the control signals output from the TCU, a real-time test system for electro-hydraulic proportional control in HILS is synchronously designed. First, the AT electro-hydraulic proportional control loop is anatomized and modeled. Second, to accelerate the calculation of models in microcontrollers, the floating point arithmetic is turned into integer type fixed-point arithmetic. Third, the hardware and the software with dual-core framework of the real-time test system are designed. Fourth, the HILS platform of AT electronic control system, including the real-time test system for electro-hydraulic proportional control, is built. Finally, steady state tests, transient tests and buffer control tests are conducted. The results verify the function of real-time test system for electro-hydraulic proportional control. The real-time test system basically meets the design demands and lays a foundation for HILS platform.
In order to facilitate the teaching of industrial processes and experiments on the twin-screw extruder control debugging,and be closer to the actual testing,to reduce the debugging costs and the risk of debugging proc...
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In order to facilitate the teaching of industrial processes and experiments on the twin-screw extruder control debugging,and be closer to the actual testing,to reduce the debugging costs and the risk of debugging process,the paper designs a hardware-in-loop simulation of twin-screw extruder experiment system which is closer to scene,low cost and high *** system through the establishment of twin-screw extruder’s mathematical model on computer to simulate the realistic system and there is hardware practicality in the computer simulation *** hardware based on C8051F020 can operate in the simulationloop in real *** computer software design, we desigh man-machine interface that is intuitive and easy to operate,can reflect twin-screw extruder main operation information ***,twin-screw extruder’s 3 heater temperature mathematical model and PID incremental control algorithm are presented.
Aiming at the development of ESP system, hardware-in-loop simulation (HILS) method based on virtual integrated technology, which combines virtual model by ADAMS/Car, virtual controller by Simulink, and LabVIEW platfor...
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ISBN:
(纸本)9781424436071
Aiming at the development of ESP system, hardware-in-loop simulation (HILS) method based on virtual integrated technology, which combines virtual model by ADAMS/Car, virtual controller by Simulink, and LabVIEW platform, is introduced. The principle of the HILS method is explained. The structure and relation among parts of the HILS system based on virtual integrated technology are discussed, and the HILS system for ESP is developed. Experiments on this system are performed and the results are analyzed and compared.
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