1、Novel integrated position measurement unit for stepping motor servo control1. IntroductionRotor position detection is important for servo system. Researchers have investigated many sensorless position detection techniques for double salient motors such as stepping motor, SRM or PMSM. The fundamental

2、 principle of these sensorless techniques is that, rotor position information can be extracted from the stator circuit measure-ments or their derived parameters such as the back EMF the winding inductance, and the ux linkage . Because of the back EMF is in proportion to speed, it can not be used at

3、standstill and low speed. Lyons proposed a technique for SRM that utilized the relationship between ux linkage and current. The method can be applied even if no non-energized phase winding is present. But the accuracy is dependent on the precise measurement of stator poles, the testing coils have fu

4、ll magnetic connection with the windings of stator, the electronic and magnetic situation of the stator windings will badly affect the sensor coils. It makes the process of signal processing to be more complex and also inuence the precision. In this paper, a new integrated position feedback unit” fo

5、r hybrid stepping motor is proposed.2. Structure of the sensorThis sensor is just produced with the motor, and has the same structure with the motor. The sensor has no electronic and less magnetic connection with the motor. The sensor is easy to manufacture and has better precision with easier signa

6、l processing circuit. The motor is a 2-phase 8-pole hybrid stepping motor that has 50 teeth on the rotor. The sensor is double salient structure, has its own stator, rotor and stator windings (testing coils); just like a small single stack 2-phase VR stepping motor. The sensors stator is aligned wit

7、h the motors stator, and its rotor is aligned with one stack of the hybrid stepping motors rotor (unaligned with the other stack). The inductance of the testing coil is the function of the rotor position. So the motors rotor position can be detected by measuring the inductance on-line. This sensor n

8、ot only for the stepping motor, but also can produced with other types of motors as a general used position sensor for servo system. The testing coils are connected to make four testing windings as the left one. Each testing winding includes two testing coils that anti-connected each other. This con

9、nection method can greatly decreases the back-EMF signal in the testing coils that produced by the magnetic couple. There is an aluminum ring between the motors rotor and the sensors rotor that making the magnetic connection between motor and sensor is very little. The structure of the sensor makes

10、it possible and easier to detect the rotor position signal.6. ConclusionsThe integrated sensor increases the length and weight of the motor, but the system is still simpler and cheaper than the position sensors used now. This type of position signal detection method has more complex mechanism than t

11、he sensorless methods. But the signal processing process is simpler and the precision is higher, and the rotor position can be detected anytime without influence of the motors situation. The integrated sensor also can be produced independent and as a normal position sensor for all kinds of rotating

12、machines. With the help of the signal processing hardware and software, this kind of sensor can give out high precision.綜合位置測(cè)量單位步進(jìn)電機(jī)伺服控制1。介紹轉(zhuǎn)子位置檢測(cè)是一種重要的伺服系統(tǒng)。研究人員就已經(jīng)在研究許多無固定位置傳感器技術(shù)用于檢測(cè)雙凸極電機(jī)，比如步進(jìn)馬達(dá),SRM或新型的永磁同步電機(jī)。這些傳感器的基本原理是,轉(zhuǎn)子位置信息可以從定子測(cè)量數(shù)據(jù)或像反電動(dòng)勢(shì)彎曲電感和磁通匝連數(shù)那些導(dǎo)出的參數(shù)中獲取。由于反電動(dòng)勢(shì)與速度是成比例的,所以它不能用于停止和制動(dòng)。里昂的一種方法,

13、提出了利用電流和磁鏈的關(guān)系。即使沒有勵(lì)磁繞組此方法也可應(yīng)用。但其準(zhǔn)確性依賴精確的測(cè)量定子極點(diǎn),測(cè)試線圈有充分的磁性與定子繞組作用,定子繞組的電磁場(chǎng)情況將很嚴(yán)重的影響傳感器線圈。它使信號(hào)處理過程更復(fù)雜、也影響精度。此文提出一種新的“集成位置反饋單元”混合式步進(jìn)電機(jī)。2。傳感器的非線性結(jié)構(gòu)這個(gè)傳感器類似一個(gè)電機(jī),并且與電機(jī)有相同的結(jié)構(gòu)。該傳感器沒有電子原件而且和電機(jī)很少有磁性相連。這個(gè)傳感器容易制造,并具有更高精度的信號(hào)處理電路。電機(jī)是一種二段式8極混合式步進(jìn)電機(jī),轉(zhuǎn)子上有50個(gè)齒。傳感器是雙凸結(jié)構(gòu),有自己的電機(jī)定子、轉(zhuǎn)子和定子繞組線圈(測(cè)試線圈),就像一個(gè)小單堆棧二段式虛擬現(xiàn)實(shí)的步進(jìn)電機(jī)。傳感器的定子對(duì)準(zhǔn)電機(jī)定子,其轉(zhuǎn)子總是和混合式步進(jìn)電機(jī)轉(zhuǎn)子的一個(gè)堆棧對(duì)齊(與其他堆棧不對(duì)齊)。測(cè)試線圈的感應(yīng)系數(shù)對(duì)轉(zhuǎn)子位置起作用。所以電機(jī)轉(zhuǎn)子位置可以通過測(cè)量即時(shí)電感得到。這個(gè)傳感器不僅用在步進(jìn)電機(jī)上,而且可以由其他類型的電機(jī)制作，作為一種普遍傳感器測(cè)量伺服系統(tǒng)。測(cè)試線圈把四個(gè)測(cè)試?yán)@組線圈連成一條。每個(gè)測(cè)試?yán)@組包括兩個(gè)與每一個(gè)反接的測(cè)試線圈。 這個(gè)連接技術(shù)可有效降低在測(cè)試?yán)@組中由磁力偶產(chǎn)生的反接信號(hào)。電機(jī)轉(zhuǎn)子和傳感器轉(zhuǎn)子之間有一個(gè)鋁環(huán),它讓電機(jī)和傳