Modeling and Simulation of Disc Brake Resistance Load in Low Speed Condition

2012 ◽  
Vol 548 ◽  
pp. 691-695
Author(s):  
Yi He ◽  
Shao Jie Du ◽  
Guang Wei Cheng

In this paper, the load simulation of tracked vehicle disc brake in low speed is discussed. The simulation of the resistance load and the control of the disc brake is researched when the resistance load loading on the test bench The simulation results show that, by controlling the input voltage of the disc brake electrohydraulic control portion, the disc brake braking torque can be controlled, the driving resistance simulation of crawler vehicle is realized. At the same time, the simulation has high accuracy, fast response speed, and has better dynamic characteristic. When the tracked vehicle is at the process of start, acceleration, deceleration, braking, steering , the engine and the transmission system mainly are in an unstable vehicle system dynamic, the load is dynamic load must be given. In order to investigate the performance of tracked vehicle HMCVT, a dynamic load [1] in the test system to simulate the loading process of tracked vehicle. Eddy current dynamometer can simulate the load [2,3] during a vehicle running a higher speed , the driving load in low speed ( including zero speed ) is simulated by disc brakes .

2016 ◽  
Vol 17 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Jie Yang ◽  
Jingang Wang ◽  
Ruixi Luo ◽  
Can Gao ◽  
Li Songnong ◽  
...  

Abstract The development trend of future voltage transformer in smart grid is non-contact measurement, miniaturization and intellectualization. This paper proposes one simulation test system of non-contact D-dot transformer for voltage measurement. This simulation test system consists of D-dot transformer, signal processing circuit and ground PC port. D-dot transformer realizes the indirect voltage measurement by measuring the change rate of electric displacement vector, a non-contact means (He et al. 2004, Principles and experiments of voltage transformer based on self-integrating D-dot probe. Proc CSEE 2014;15:2445–51). Specific to the characteristics of D-dot transformer signals, signal processing circuits with strong resistance to interference and distortion-free amplified sensor output signal are designed. WIFI wireless network is used to transmit the voltage detection to LabVIEW-based ground collection port and LabVIEW technology is adopted for signal reception, data processing and analysis and other functions. Finally, a test platform is established to simulate the performance of the whole test system of single-phase voltage transformer. Test results indicate that this voltage transformer has sound real-time performance, high accuracy and fast response speed and the simulation test system is stable and reliable and can be a new prototype of voltage transformers.


2021 ◽  
Vol 118 (21) ◽  
pp. e2100736118
Author(s):  
Yang Zhang ◽  
Liang Fu

We propose a method for broadband long-wavelength photodetection using the nonlinear Hall effect in noncentrosymmetric quantum materials. The inherently quadratic relation between transverse current and input voltage at zero magnetic field is used to rectify the incident terahertz or infrared electric field into a direct current, without invoking any diode. Our photodetector operates at zero external bias with fast response speed and has zero threshold voltage. Remarkably, the intrinsic current responsivity due to the Berry curvature mechanism is a material property independent of the incident frequency or the scattering rate, which can be evaluated from first-principles electronic structure calculations. We identify the Weyl semimetal NbP and ferroelectric semiconductor GeTe for terahertz/infrared photodetection with large current responsivity without external bias.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ting Zhang ◽  
Shibin Li

AbstractIn this manuscript, the inorganic perovskite CsPbI2Br and CsPbIBr2 are investigated as photoactive materials that offer higher stability than the organometal trihalide perovskite materials. The fabrication methods allow anti-solvent processing the CsPbIxBr3−x films, overcoming the poor film quality that always occur in a single-step solution process. The introduced diethyl ether in spin-coating process is demonstrated to be successful, and the effects of the anti-solvent on film quality are studied. The devices fabricated using the methods achieve high-performance, self-powered and the stabilized photodetectors show fast response speed. The results illustrate a great potential of all-inorganic CsPbIxBr3−x perovskites in visible photodetection and provide an effective way to achieve high performance devices with self-powered capability.


2021 ◽  
Vol 9 (14) ◽  
pp. 4799-4807
Author(s):  
Yong Zhang ◽  
Weidong Song

P-CuZnS/n-GaN UV photodetector is prepared by a simple chemical bath deposition, showing excellent self-powered properties, including ultrahigh on/off ratio (3 × 108), fast response speed (0.14/40 ms) and large detectivity of 3 × 1013 Jones.


2012 ◽  
Vol 472-475 ◽  
pp. 1036-1039
Author(s):  
Chong Yang ◽  
Ke Zhang ◽  
Mei Bai Lu

First a new autopilot design model is presented for the interceptor missile with the blended aerodynamic lift and reaction jet. The reaction jet can improve the response speed, but the structure of control system becomes more complex. Therefore how to design control strategy properly is an urgent problem. Second, considering the discrete property of the lateral pulse jet thrusters and the continuous property of the aerodynamic fins, a kind of ADRC (active disturbance rejection control) autopilot system was designed for the aerodynamic lift/reaction jet missile. Finally, through a testing in the simulation of MATLAB, it is shown that, due to the sufficient utilization of the reaction jet, there is a significant improvement in the fast response and robust performance of the proposed controller. It is applicable to design the autopilot of aerodynamic lift and reaction jet blended missile.


2012 ◽  
Vol 594-597 ◽  
pp. 460-464
Author(s):  
Qian Shi ◽  
Kui Zhou ◽  
Qiang Li

The mechanism of dynamic tri-axial test is introduced in this paper and the dynamic responses of silt soft clay at Zhoushan are studied using a dynamic tri-axial test system. The laws of pore pressure build-up of the silt clay are obtained which are affected by the consolidation pressure and dynamic load. The greater the consolidation pressure and the dynamic loading is, the more the build-up of pore pressure is. However, the dynamic load has minor effect on pore pressure build-up under the anisotropic consolidation.


2021 ◽  
Vol 13 (6) ◽  
pp. 7498-7509
Author(s):  
Yujie Yan ◽  
Qizhen Chen ◽  
Xiumei Wang ◽  
Yaqian Liu ◽  
Rengjian Yu ◽  
...  

Author(s):  
Yan Yin ◽  
Jiusheng Bao ◽  
Jinge Liu ◽  
Chaoxun Guo ◽  
Tonggang Liu ◽  
...  

Disc brakes have been applied in various automobiles widely and their braking performance has vitally important effects on the safe operation of automobiles. Although numerous researches have been conducted to find out the influential law and mechanism of working condition parameters like braking pressure, initial braking speed, and interface temperature on braking performance of disc brakes, the influence of magnetic field is seldom taken into consideration. In this paper, based on the novel automotive frictional-magnetic compound disc brake, the influential law of magnetic field on braking performance was investigated deeply. First, braking simulation tests of disc brakes were carried out, and then dynamic variation laws and mechanisms of braking torque and interface temperature were discussed. Furthermore, some parameters including average braking torque, trend coefficient and fluctuation coefficient of braking torque, average temperature, maximum temperature rise, and the time corresponding to the maximum temperature rise were extracted to characterize the braking performance of disc brakes. Finally, the influential law and mechanism of excitation voltage on braking performance were analyzed through braking simulation tests and surface topography analysis of friction material. It is concluded that the performance of frictional-magnetic compound disc brake is prior to common brake. Magnetic field is greatly beneficial for improving the braking performance of frictional-magnetic compound disc brake.


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1561
Author(s):  
Hery Tri Waloyo ◽  
U Ubaidillah ◽  
Dominicus Danardono Dwi Prija Tjahjana ◽  
Muhammad Nizam ◽  
Muhammad Aziz

The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analytical and 3D modelling, the amount of braking torque at a low speed was found to have an average error for the equation using a correction factor of 1.78 Nm, while after repairing, a value of 1.16 Nm was obtained. For the overall speed, an average error of 14.63 Nm was achieved, while the proposed equation had a small difference of 1.79 Nm. The torque difference from the calculation results of the proposed model with the measurement value in the experiment was 4.9%. Therefore, it can be concluded that the proposed equation provided a better braking torque value approach for both low and high speeds.


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