【機械類畢業(yè)論文中英文對照文獻翻譯】電動助力轉向的離線檢測
【機械類畢業(yè)論文中英文對照文獻翻譯】電動助力轉向的離線檢測,機械類畢業(yè)論文中英文對照文獻翻譯,機械類,畢業(yè)論文,中英文,對照,對比,比照,文獻,翻譯,電動,助力,轉向,離線,檢測
附錄A：英文資料
Offline Detection of Electric Power Steering (EPS)
Xu Hanbin Zhang Zhongfu
School of Mechantronic Engineering Wuhan University of Technology.
Wuhan 430070, CHINA\
Abstract: Increasing use of electric power steering (EPS) systems, which affect vehicle dynamic behavior, has prompted the need for a more effective method of testing electric power steering systems, especially to electric control unit (ECU) in EPS. This research aims at building EPS off-line platform for realization of performance detection. First, the control logic on EPS is analyzed, and all kinds of input signals influencing on EPS are analyzed and modeled. They include engine velocity, vehicle velocity, self-diagnosis signal, starter signal and the steering angle. Then, the hardware- in-the-loop simulation (HILS) system is designed. The industrial computer is selected as the main test platform with some ISA-bus cards. In addition, the conversion interface is designed to suit the in-out need of EPS and the industrial computer. The system will be achieved with both simplicity and usability taken into account. The correlative control software is also developed with the good friendly interface. It can realize the storage of the testing data automatically. At last, the hardware-in- the-loop simulation system that can implement an actual load (prepared) torque delivered to the steering column is achieved. Experimental studies show that the hardware-in-the-loop simulation system can satisfy the need of off-line detection.
Keywords：simulation, electric power steering, hardware-in-the-loop
I. Introduction
Electric power steering (EPS) is more energy efficient and environmentally compatible. It consumes approximately one-twentieth the energy of conventional hydraulic power steering systems and, as it does not contain any oil, it does not pollute the environment both when it is produced and discarded. As a result, this motivates the great increase of EPS-equipped vehicles recently.
Although electric power steering systems offer significant advantages over their hydraulic counterparts, electric motor technology and controls had not reached the point where they could be used in this application until just recently. Thus, it is very necessary to improve EPS quality continuously, especially to the core of EPS: electric control unit (ECU). It certainly leads to more tests on EPS, and the tests are also very important for ECU development. It is a problem to process testing in the dynamics of unavailable hardware (not built yet or impossible or inconvenient to access).
Now hardware-in-the-loop simulation (HILS) is introduced. Test in hardware-in-the-loop simulation is a viable alternative, allowing new electronic control units and software to be tested largely in a virtual environment, without real vehicles or prototypes.
This report outlines the construction of the offline EPS detection systems, as well as their main components. And EPS experiment based on HILS has been achieved.
II. EPS System
A. Principle of EPS
The EPS system consists of a torque sensor, which senses the driver’s movements of the steering wheel; an ECU, which performs calculations on assisting force based on signals from the torque sensor; a motor, which produces turning force according to output from the ECU; and a reduction gear, which increases the turning force from the motor and transfers it to the steering mechanism. EPS is available in two types: a column type in which the reduction gear is located directly under the steering wheel, and a pinion type in which the reduction gear is attached to the pinion of the rack and pinion assembly. Each type of EPS system is speed-sensitive—vehicle speed and engine rotation signals are input from the vehicle into the ECU. Fig.1 shows a vehicle with column-type EPS.
The main purpose of any power steering system is, of course, to provide assist to the driver. This is achieved by the torque sensor, which measures the driver’s torque and sends a signal to the controller proportional to this torque. The controller also receives steering position information from the position sensor that is collocated with the torque sensor and together they make up the Sensor. The torque and position information is processed in the controller and an assist command is generated. This assist command is further modulated by the vehicle speed signal, which is also received by the controller. This command is given to the motor, which provides the torque to the assist mechanism. The gear mechanism amplifies this torque, and ultimately the loop is closed by applying the assist torque to the steering column. The power source is from the battery (12V).
FIG.1 EPS System
B. Input and Output Signals on ECU
The three primary roles and corresponding functions of the ECU in EPS systems are :
1). Power steering functions
Generate assisting force (motor current) pursuant to vehicle speed and input torque to ensure appropriate steering power throughout vehicle speed range.
2). Self-diagnosis and fail-safe functions
Monitor the EPS system components for failure. Upon detecting any failure, controls EPS functions depending on the influence of the failure and warns the driver. Also, stores the failure location in the ECU.
3). Communication functions
Data stored in the ECU can be read and EPS system functions checked using external communication equipment.
To realize a performance detection of the ECU, the input and output signals on the ECU need studying.
Input :
a. Engine rotation: 0-12V square wave
b. Vehicle speed: 0-5V square wave
c. Torque voltage
Main edge :The bigger is the left steering angle, the smaller is the output voltage. The bigger is the right steering angle, the more is the output voltage. The output is 2.5V at the straight position.
Sub edge: quite the contrary.
d. Ignition signal : on-off switch
Output :
a. Clutch switch : on-off switch
b. Motor current : 0 -30A
c. EPS status :0-12V variable interval square wave
In addition, self-diagnosis on-off switch will be properly earthed when the EPS needs maintenance. The switch is not earthed in the normal usage of EPS.
III. Hardware-in-the-loop simulation
Hardware-in-the-loop simulation system has been built to realize the offline detection of EPS as Fig.2. The industrial computer is regarded as the testing platform with PCL-836 card, PCL-730 card, PCL-726 card and PCL-813B card
The PCL-836 card is a multifunction counter-timer and digital I/O add-on card for IBM PC/XT/AT and compatibles. It provides six 16-bit down counters, a 10 MHz crystal oscillator time base with divider and general purpose 16-bit TTL input and output ports.
Two channels in the card are used for detection. Channel 0 is used to produce the square signal for simulating vehicle velocity (max 100 Hz). Channel 1 produces the square for engine velocity.(max 100 Hz).The square waves are all TTL. Because the ECU needs 0-12V square wave as engine rotation, the wave from channel 1 must be exchanged through the circuit. The relationship between vehicle velocity and the simulating square is 60 km/h to 43 Hz.
The PCL-730 card offers 32 isolated digital I/O channels (16 DI and 16 DO) and 32 TTL digital I/O channels (16 DI and 16 DO) on a PC add-on card. Providing 1000 V isolation, each I/O channel corresponds to a bit in a PC I/O port, making the PCL-730 very easy to program. In the HILS system, connector CN1 Isolated output is selected for ignition and self-diagnosis signal. Pin IDO0 in the CN1 is for ignition, and IDO 1 for self-diagnosis. Connector CN2 Isolated input is selected for the signal of EPS status lamp. The system will translate the different interval square from pin IDI 0 in the CN2 to the special code, and show the information about the ECU status.
The PCL-813 is a 32 channels single-ended isolated analog input card with 12-Bit resolution A/D conversion. It is easy to use and cost effective IBM PC/XT/AT compatible data acquisition card.
Three A/D channels are employed in the system. AI0 (Analog input 0) is used to sample the motor current from ECU. AI1（Analog input 1) is used to sample the voltage from the main edge of the torque sensor, and AI2（Analog input 2) to exchange the one from the sub edge .
The PCL-726 provides six independent D/A output channels on a single PC-BUS add-on card. Each channel has 12 bit resolution, double buffered D/A converters. Channel 0 is employed to simulate loading the torque on the column of EPS.
FIG.2 Simulation System
In addition, software running in the system is developed based on Advantech device driver library ADSAPIBC.LIB. The Advantech Device Driver library supports event functions. It notifies the program by posting messages when events occur within the device. The interface function in the library is so simple that the programming time is shortened. The I/O addresses in response to the cards are 240H (PCL-836), 300H (PCL-730), 2C0H (PCL-726) and 210H (PCL-813).
Ⅳ.Experiment Based on HILS
According to the different simulating vehicle speed set by the HILS system, the curves of the assistant current vs. steering torque are get from the experiments (Fig.4).
Fig.3 shows the expected control strategy on the left steering. It absents the steering assistance current vs. steering torque curves based on vehicle speed. The faster is the speed, the less is the assistance current.
Fig.4 is the steering assistance current vs. steering torque curves based on vehicle speed in the HILS. The experiment is developed from low speed to high speed. It has recorded the curves on the steering assistance current vs. the output voltage of the torque sensor when the simulating vehicle speed was respectively 2Hz (2.8 km/h), 4Hz (5.6 km/h), 6Hz (8.5 km/h), 8Hz (11.3 km/h), 10Hz (14.1 km/h), 20Hz (28.3 km/h), 40Hz (56.8 km/h), 60Hz (84.7 km/h), 80Hz (113.0 km/h) or 100Hz (141.3 km/h). Comparison between the two figures shows that the experiment results is well suited to the expected ones at 20Hz -100Hz, but the experiment results is higher than the expected ones at 2Hz-10Hz. In sum, the developed HILS could better satisfy the need of the offline detection.
FIG.3 Assistance current vs. torque voltage(expected )
FIG.4 Assistance current vs. torque voltage(experiment)
Ⅴ.Torque Voltage
The hardware-in-the-loop simulation on electric power steering is built, and the first experiment has also achieved. The result proves that the HILS system is available.
Such tests are very systematic and also completely safe, even when critical thresholds are exceeded, while allowing ECU errors to be reproduced whenever and however required.
The hardware-in-the-loop simulation is a cost- effective way to shorten design times and improve product quality. And it is very easy to test the new EPS control algorithm in the system.
As we have seen above, there are some problems in the developed system too. The recorded assistance current is a little bigger than the expected one at low vehicle speed. This shows that the experiment ways would be improved still.
附錄B：英文資料翻譯
電動助力轉向的離線檢測
徐漢斌 張忠福
武漢理工大學機械工程學院
武漢430070，中國
摘要：影響車輛的動態(tài)行為的電動助力轉向系統(tǒng)正被越來越多地使用，這急需一個更有效的測試電動助力轉向系統(tǒng)的方法，特別是對于電動轉向系統(tǒng)中的電控單元。本研究旨在創(chuàng)建EPS（電動助力轉向系統(tǒng)）的離線平臺來實現(xiàn)其性能檢測。首先，對EPS的控制邏輯進行分析，對各種輸入信號對EPS的影響進行分析和模擬。它們包括發(fā)動機速度，車速，自診斷信號，啟動信號和轉向角。然后設計HILS（硬件在環(huán)仿真）系統(tǒng) ，選擇工業(yè)電腦和一些ISA總線卡作為主要測試平臺。其次，轉換接口的設計要適合EPS和工業(yè)電腦輸入輸出的需要。該系統(tǒng)要把實現(xiàn)既簡單又實用考慮進去，相關控制軟件要要實現(xiàn)良好的接口。它能實現(xiàn)對測試數(shù)據(jù)的自動存儲。最后，HILS系統(tǒng)可實現(xiàn)以實際轉矩傳遞到轉向系轉向管柱上。實驗研究表明，硬件在環(huán)仿真系統(tǒng)中能夠滿足離線檢測的需要。
關鍵詞：仿真，電動助力轉向，硬件環(huán)路。
1 介紹
電動助力轉向更能做到能量高效，環(huán)境相容。它消耗的能量約為傳統(tǒng)的液壓動力轉向系統(tǒng)的二十分之一，并且，它不含任何油，不論是生產(chǎn)還是報廢它都不污染環(huán)境。因此，這激發(fā)了越來越多地車輛裝備EPS。
雖然電動助力轉向系統(tǒng)相對于液壓動力系統(tǒng)有巨大的優(yōu)勢，但電動機和控制技術沒有達到它們能被應用的程度，直到最近。因此，不斷改進EPS的質(zhì)量十分必要，特別是EPS電動控制單元的核心。這當然導致了對EPS的更多測試，這些測試對ECU的發(fā)展也十分重要。這對于不存在硬件（沒有建立或不能或不便訪問）的動態(tài)過程測試是一個問題[3]。
現(xiàn)在對HILS進行介紹[5]。在HILS系統(tǒng)中測試時一種可行的選擇，主要是讓新的電控單元和軟件在一個虛擬的沒有汽車或原型的環(huán)境中進行測試。這份報告概述了EPS離線診斷系統(tǒng)的創(chuàng)建，以及其主要組件。因此EPS基于HILS的實驗已經(jīng)達到。
2 EPS系統(tǒng)
2.1 EPS的原則
EPS系統(tǒng)包含一個扭矩傳感器，它來測量駕駛員對方向盤加載的運動；一個ECU，它接收來自扭距傳感器的信號再進行計算所需加載的助力；一個電機，根據(jù)ECU的輸出產(chǎn)生助力；還有一個減速齒輪，來增大來自電機的助力，再把它傳到轉向器中。EPS有兩種類型：轉向軸助力式：減速齒輪直接位于轉向盤下；齒條助力式：減速齒輪與齒輪齒條相連。每個類型的EPS系統(tǒng)都有速度感應—車速和發(fā)動機轉速從汽車輸入到ECU。圖1是柱型EPS汽車[2]。
當然，任何電動助力轉向系統(tǒng)的目的都是為駕駛員提供幫助。傳感器實現(xiàn)了這一目的，它測量司機的轉矩，并發(fā)送一個轉矩比的信號到控制器。該控制器還從與轉矩傳感器布置在一起的位置傳感器那接收到了位置信息。控制器處理轉矩和位置信息，并生成一個協(xié)助命令。此命令將進一步調(diào)整由控制器收到的車速信號。此命令傳到電機，它則向助力裝置提供轉矩。減速齒輪放大了轉矩，最終由向轉向柱提供助力使得環(huán)路封閉。動力來源于12V的電池。
圖1 EPS系統(tǒng)
2.2 ECU的輸入和輸出信號
EPS系統(tǒng)中的ECU的三個主要作用和相關功能是：
(1) 動力轉向功能
依據(jù)車速和輸入轉矩產(chǎn)生助力（電機電流）以確保在整個車速范圍內(nèi)有合適的轉向功率。
(2) 自我診斷和故障保險功能
監(jiān)測EPS系統(tǒng)中的故障組件。在檢測到任何故障時，控制EPS向故障影響的功能，向駕駛員發(fā)出警告。然后，在ECU中記錄故障位置。
(3) 通信功能
ECU中的存儲數(shù)據(jù)可以被讀取，通過使用外部設備可以檢查EPS系統(tǒng)的功能。為了實現(xiàn)ECU的性能檢測，ECU的輸入輸出信號需要研究。
1) 輸入
a)發(fā)動機轉速：0~12V方波
b)車速：0~5V方波
c)轉矩電壓
主要優(yōu)勢：左邊的轉向角越小，輸出電壓越小。右邊的轉向角越大，輸出電壓越大。直線位置輸出電壓為2.5V。
次要優(yōu)勢：恰恰相反。
d)點火信號：通斷開關
2) 輸出
a)離合器開關：通斷開關
b)電機電流：0~30A
c)EPS狀態(tài)：0~12V可變間隔方波
此外，當EPS系統(tǒng)需要維修時，自診斷的通斷開關會正確接地。在正常使用EPS時，該開關不會接地。
3 硬件在環(huán)路中的仿真
HILS系統(tǒng)已經(jīng)建成，用來實現(xiàn)如圖2所示的EPS的掉線檢測。此工業(yè)電腦被視為擁有PCL-836卡，PCL-730卡，PCL-726卡和PCL-813B卡的測試平臺[4]。
PCL-836卡是一個多功能計數(shù)—定時器和IBM PC/XT/AT的數(shù)字I/O插件相兼容的卡。它提供了6個16位計數(shù)器，基于驅(qū)動的10MHz的晶體振蕩器和通用的16位TTL輸入和輸出端口。
卡中的兩個通道是用于檢測。通道0是用于產(chǎn)生方波信號來模擬車速（最大100Hz）。通道1為模擬發(fā)動機速度產(chǎn)生方波信號（最大100Hz）。方波信號都是TTL型。因為需要0—12V的方波作為發(fā)動機的轉速，來自通道1的方波必須通過電路轉換。車速與模擬方波的關系是60Km/h對應43Hz。
PCL-730卡在電腦附加卡上提供32個隔離的數(shù)字I/O通道（16個DI和16個DO）和32個TTL數(shù)字I/O通道（16個DI和16個DO）。提供1000V的隔離電壓，每一個I/O通道對應于電腦I/O口的一位，使PCL-730十分容易編寫。在HILS系統(tǒng)中，連接器CN1隔離輸出用來選擇點火和自診斷信號。P在CN1中的IDO0中表示點火，在IDI0中表示自診斷。連接器CN2隔離輸出用來選擇EPS狀態(tài)燈的信號。這個系統(tǒng)將把來自ID1和ID2的P的不同間隔波翻譯成特殊代碼，顯示ECU狀態(tài)的信息。
PCL-813是一個32通道的單端隔離類似于輸入卡的12位的A/D轉換口。它易于使用且具有IBM的PC/XT/AT兼容的數(shù)據(jù)采集卡。
該系統(tǒng)擁有三個A/D通道。AIO用于采集來自ECU的電機電流。AI1用于采集來自轉矩傳感器主邊緣的電壓。AI2用來把它交換到副邊緣。
PCL-726在一個單獨的PC總線插槽上提供6個獨立的D/A輸出通道。每個通道具有12位分辨率，雙緩沖D/A整流器。通道0用來模擬向EPS轉向柱上加載轉矩。
圖2 仿真系統(tǒng)
另外，該系統(tǒng)運行的軟件是基于Advantech裝置驅(qū)動數(shù)據(jù)庫ADSAPIBC.LIB開發(fā)的。此裝置驅(qū)動數(shù)據(jù)庫支持事件功能。當事件發(fā)生在裝置中時，它通過發(fā)布消息來通知程序。接口功能是如此簡單以至于編程時間可以縮短。I/O對應卡中的地址是240H(PCL-836)，300H(PCL-730)，2C0H(PCL-726)和210H(PCL-813)。
4 基于HILS的實驗
根據(jù)由HILS系統(tǒng)設置的不同模擬車速，輔助曲線的電流和轉向轉矩來自實驗。（圖4）
圖3顯示在左轉向的預期控制策略。它缺乏基于車速的轉向輔助電流和轉向轉矩曲線。速度愈快，輔助電流愈小。
圖4是在HILS系統(tǒng)中基于車速的轉向輔助電流和轉向轉矩曲線。實驗的發(fā)展是從低速高速。當模擬車速分別為2Hz(2.8km/h)，4Hz(5.6km/h)，6Hz(8.5km/h)，8Hz(11.3km/h) ，10Hz(14.1km/h)，20Hz(28.3km/h)，40Hz(56.8km/h)，60Hz(84.7km/h)，80Hz(113.0km/h)或100Hz(141.3km/h)時，記錄下轉向輔助電流的曲線和轉矩傳感器輸出的電壓。比較兩組數(shù)據(jù)表明，實驗結果非常適合那些預期在20Hz~100Hz的，但是實驗結果要高于那些預期在2Hz~10Hz的。總之，HILS的發(fā)展能更好的滿足掉線檢測的需要。
圖3 助力電力流和轉矩電壓（期望值）
圖4 助力電流和轉矩電壓（實驗值）
5 結論
電動助力轉向的硬件環(huán)仿真已經(jīng)建立，第一個實驗也已經(jīng)完成。該實驗結果證明HILS系統(tǒng)可用。
這種測試是非常系統(tǒng)的，也是完全安全的，即使苛刻的臨界值被超過，仍然準許ECU再次報錯，不論何時何種需要。
此硬件環(huán)仿真是一種縮短設計時間和改善產(chǎn)品質(zhì)量的有效方法。而且在系統(tǒng)中很容易測試新的EPS控制算法。
正如我們上面所看到的，在系統(tǒng)的開發(fā)中還有一些問題。在低速時，記錄的輔助電流要略低于期望的。這表明實驗還有改善的地方。
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