电子指南针中英文翻译

Title：CALIBRATING METHOD FOR ELECTRONIC COMPASS Electronic compass is an electronic compass by measuring the Earth's magnetic field to achieve directional navigation device, it is an important navigational tool that can provide real-time data objects heading and attitude, and has a small size, low cost, fast response , no accumulated error, etc., are widely used in mobile robots, vehicles, aircraft and other orientation subsystem; However, due to the electronic compass is based on magnetic principles calculations magnetic bearings, their work environment, in addition to other external magnetic field Earth's magnetic field will inevitably affect the output of the electronic compass, resulting in errors affect measurement accuracy. Therefore, how to reduce outside interference precision of its output is engineering applications must be addressed.

Electronic compass the existing literature has proposed several possible compass error compensation method. Yuen Chee Wing paper, "three-axis magnetic heading sensors full attitude error compensation 'proposed compass error into quadrature error, zero and sensitivity errors were compensated, high compensation accuracy of the method, but in the compensation process requires non-magnetic turntable , but also the computer automatically when the measured rotation compass X and Y-axis sensor output maximum, minimum, the calibration process is complex and requires high equipment; HIGHW AY AND TRANSPORTA TION Wang Jiaxin paper "Development of high-precision electronic compass" and Shao Tingting, ROCKETS paper "electronic compass tilt and Luo slip compensation algorithm research," the least square method to compensate for the electronic compass, the method requires Compass 0 ° ~ 360 ° rotation average sampling, operation is relatively cumbersome and The amount of data samples of different sizes will have a greater impact fitting result, the amount of data is too small, the compensation effect is not good, too much data can cause performance degradation fitting; Yangxin Yong, Huang Shengguo paper "magnetic heading measurement system Error Correction Method "and Qi Zhang, Liang-shui Lei, Jiang Fan, Song Liu's paper" Autocalibration of a magnetic compasswithout heading reference "error ellipse hypothesis is proposed based on the model compensation method, because only a hypothetical model ellipse based on the experimental experience suggested that the lack of theoretical deduction, the compensation effect is not very satisfactory; Chao Min, Jiang Oriental, Wen rainbow paper, "magnetic compass error analysis and calibration" using an analytical method to establish the direction of the magnetic measurement system is more accurate

models, and electronic compass compensation in the horizontal conditions, but the compensation process to identify more parameters (up 9), and the results show the compensation effect is similar to oval hypothetical model; Hao Zhenhai, Huang Shengguo paper, "based on a combination of differential magnetic compass heading system." proposed a "differential magnetic compass" (DMC, Differential Magnetic Compasses) design program, which uses two identical magnetic compass to determine whether the system is a combination of low-frequency interference occurs, if the system glitches did not happen, then the use of magnetic compass navigation, low-frequency interference will occur if the system switches to the gyroscope system navigation. The program does not substantially improve the magnetic compass measurement accuracy, and the navigation program consists of a plurality of magnetic compass and gyroscope structure, will lead to greatly increase the cost; Lu Wang, Zhao Zhong and other paper "Magnetic Compass Error Analysis and Compensation" using BP neural network error model, and use LM learning algorithm to train the network, the method need not 0 ° ~ 360 ° within the average sampling, with a neural network can be approximated function with arbitrary precision characteristics, with high compensation accuracy, but the BP neural network convergence is slow, the right to set initial values need to be very careful, and easy to fall into local minimum.

In summary, the current electronic compass calibration methods are the main method of least squares, oval assumption France, BP neural network method, etc. These methods are more cumbersome calibration procedure or the existence of the necessary instruments for demanding calibration or calibration issues such as lack of precision.

It is an electronic compass by measuring the Earth's magnetic field to achieve directional navigation device, it is an important navigational tool that can provide real-time data objects heading and attitude, and has a small size, low cost, fast response , no accumulated error, etc., are widely used in mobile robots, vehicles, aircraft and other orientation subsystem; However, due to the electronic compass is based on magnetic principles calculations magnetic bearings, their work environment, in addition to other external magnetic field Earth's magnetic field will inevitably affect the output of the electronic compass, resulting in errors affect measurement accuracy. Therefore, how to reduce outside interference precision of its output is engineering applications must be addressed.

In order to simplify the calibration procedure, reducing the requirements for the necessary

equipment and to improve calibration accuracy, the present invention designed an electronic compass calibration method, the calibration method based on adaptive differential evolution method and Fourier neural network (Adaptive Differential Evolution and Fourier Neural Network, ADE-FNN), by means of Fourier neural network modeling of the electronic compass error, the neural network using orthogonal Fourier series excitation function as a network, and uses adaptive differential evolution algorithm to train the network weights, get more precise The error model to compensate for the measured values of the compass, so as to improve the precision of the compass.

Differential evolution method based on adaptive neural networks and Fourier electronic compass calibration methods, including access to training samples, the use of Fourier neural network (FNN) build error compensation model and the use of adaptive differential evolution algorithm (ADE) to train the neural network weight value of three parts, to achieve the specific steps are as follows:

Step one, get training samples;

Step two, identified neural network structure;

Step three, to create an electronic compass error model and choose the training targets;

Step four: According to the training sample using an improved adaptive differential evolution algorithm for training the neural network;

Step Five, will optimize the neural network weights obtained values into the neural network to obtain a more accurate compensation models;

Step Six, the electronic compass output measurement values into compensate for neural network input and output compensation value.

The invention took into account the impact of measurement precision electronic compass, proposes a differential evolution method based on adaptive neural networks and Fourier concentration calibration method to compensate, on the one hand to simplify the calibration process, that is just the turntable rotate (no uniform rotation) electronic compass one week for training samples and the corresponding true value; hand with better results, ie, more precisely offset outside interference, improve measurement accuracy.

The compensation method with neural network structure is simple, easy to implement, and can approximate nonlinear functions with arbitrary precision, and has good generalization

capability advantages.

Orthogonal Fourier function as the excitation function neural network, the nonlinear optimization problem into a linear optimization problem, which greatly improve the convergence speed, avoid falling into local minimum.

Using adaptive differential evolution algorithm to train the neural network, relying on a system to avoid the initial value problem of a priori knowledge is difficult to choose; while the improved differential evolution algorithm in the initial stages of a strong global search ability, as much as possible to find the global optimum, but at a later stage there is a strong local search ability to improve convergence rate and solution accuracy; therefore the algorithm has strong global search ability, can effectively prevent premature convergence, and algorithms good stability.

How Does a Digital Compass Work?

An electronic compass such as the Wayfinder uses a patented magnetic sensor technology that was first developed by PNI, Inc. for the U.S. military. This technology is called " magneto-inductive" and is the largest advancement in compass technology since the fulxgate was invented 60 years ago. The magneto-inductive technology is able to electronically sense the difference in the earth's magnetic field from a disturbance caused by external elements such as ferro-magnetic materials and the magnetic field generated by automobile electrical systems. WayFinder digital compass has an embedded micro controller that subtracts the automobile magnetic field (the distortion) from the stronger earth magnetic fields resulting in a highly accurate compass reading.

Compass Installation

The performance of a compass will greatly depend on its installation location. A compass relies on the earth’s magnetic field to provide heading. Any distortions of earth magnetic field by other sources such as a car massive iron components should be compensated for in order to determine an accurate heading. Sources of magnetic fields in any automobile include permanent magnets mostly in its audio speakers, motors, electric currents flowing in its wiring—either dc or ac, and ferro-magnetic metals such as steel or iron. The influence of these sources of interference on an electronic compass accuracy can be greatly reduced by placing the compass far away from them. Some of the field effects can be compensated by way of calibrating the compass for a defined

location in terms of magnetic interference. However, it is not always possible to compensate for time varying magnetic fields; for example, disturbances generated by the motion of magnetic metals, or unpredictable electrical current in a nearby power lines. Magnetic shielding can be used for large field disturbances from motors or audio speakers. The best way to reduce disturbances is distance. Also, never enclose the compass in a magnetically shielded metallic housing. Compass Tilt Errors

Heading errors due to a tilt depend somewhat on geographic location. At the equator, tilt errors are less critical since the earth's field is strictly in the horizontal plane. This provides larger X and Y readings and little of the Z component correction near the magnetic poles, tilt errors are extremely important—since there is less X,Y field and more of the Z component. Tilt errors are also dependent on the heading.

Magnetic Field Distortions

Nearby Ferrous materials is another consideration for heading inaccuracy. Since heading is based on the direction of the earth's horizontal field a digital compass must be able to measure this field with lesser influence from other nearby magnetic sources or disturbances.

The amount of disturbance depends on the material content of the platform and connectors as well as ferrous objects moving nearby. When a ferrous object is placed in a uniform magnetic field it will exert an influence. This object could be a steel bolt or bracket near the compass or an iron door latch close to the compass. The net result is a characteristic distortion, or anomaly to the earth’s magnetic field that is unique to the shape of the object.

Magnetic distortions can be categorized as two types—hard iron and soft iron effects. Hard iron distortions arise from permanent magnets and magnetized iron or steel on the compass platform. These distortions will remain constant and in a fixed location relative to the compass for all heading orientations. Hard iron effects add a constant magnitude field component along each axes of the sensor output.

To compensate for hard iron distortion is usually done by rotating the compass and platform (your car) in a circle and measure enough points on the circle to determine this offset. Once found, the (X,Y) offset can be stored in memory and subtracted from every reading. The net result will be to eliminate the hard iron disturbance from the heading calculation.

The soft iron distortion arises from the interaction of the earth’s magnetic field and any

magnetically soft material surrounding the compass. Like the hard iron materials, the soft metals also distort the earth’s magnetic field lines. The difference is the amount of distortion from the soft iron depends on the compass orientation.

What Is True North?

It is well known that the earth's magnetic poles and its axis of rotation are not at the same geographical location. They are about 11.5°rotation from each other. This creates a difference between the true north, or grid north, and the magnetic north, or direction a magnetic compass will point. Simply it is the angular difference between the magnetic and true north expressed as an Easterly or Westerly variation. This difference is defined as the variation angle and is dependent on the compass short duration, making a magnetic compass a useful navigation tool.

Compass Calibration

Each calibration method is associated with a specified physical movement of the compass platform in order to sample the magnetic space surrounding the compass. The Hard and Soft iron distortions will vary from location to location within the same platform. The compass has to be mounted permanently to its platform to get a valid calibration.

A particular calibration is only valid for that location of the compass. If the compass is re-oriented in the same location, then a new calibration is required. It is possible to use a compass without any calibration if the need is only for repeatability and not accuracy.

题目：校准电子罗盘的方法

电子罗盘是一种通过测量地球磁场来实现定向导航功能的装置，它是一种重要的导航工具，能实时提供物体的航向和姿态数据，且具有体积小、成本低、响应速度快、无累积误差等特点，被广泛应用于移动机器人、车辆、飞行器等的定向子系统中；然而，由于电子罗盘是根据地磁原理计算磁方向角，其工作环境中除地球磁场的其他外界磁场不可避免的会对电子罗盘的输出造成影响，从而产生误差影响测量精度。因此，如何降低外界干扰对其输出的精度的影响是工程应用中心必须解决的问题。

现有的文献已经提出了几种可行的罗盘误差补偿方法。袁智荣的论文《三轴磁航向传感器的圈子太误差补偿》提出将罗盘误差分为正交误差、零位于灵敏度误差分别进行补偿，该方法补偿精度较高，但是在补偿过程中需要无磁转台，而且需要计算及自动测出罗盘旋转一周时X和Y周传感器输出的最大、最小值，其标定过程较复杂，且对设备要求较高；李希

胜、王家鑫的论文《高精度电子罗盘的研制》以及邵婷婷、马建仓的论文《电子罗盘的倾斜角及罗差补偿算法研究》采用最小二乘法对电子罗盘进行补偿，该方法需要对罗盘在0 ° ~ 360 °旋转式平均采样，操作较繁琐，而且采样的数据量的大小不同会对拟合结果长生较大的影响，数据量太小，补偿效果不好，数量太大，会造成性能恶化的拟合；杨新勇、黄圣国的论文《磁航向测量系统误差修正方法研究》以及Qi Zhang、Liang-shui Lei、Jiang Fan、Song Liu的论文《Autocalibration of a magnetic compasswithout heading reference》提出一种基于椭圆假设误差模型的补偿方法，由于椭圆假设模型仅是根据实验经验提出，缺乏理论论证，补偿效果并不是很理想；晁敏、将东方、文彩虹的论文《磁罗盘误差分析与校准》采用分析法建立磁方向测量系统较为精确地模型，并对电子罗盘在水平条件下进行补偿，单补偿过程中要补偿的参数较多（达到9个）而且其结果显示其补偿效果类似椭圆假设模型；郝振海、黄圣国的论文《基于差分磁罗盘的组合航向系统》提出一种“茶粉磁罗盘”（DMC,Differential Magnetic Compasses）的设计方案，该方案利用两个完全相同的磁罗盘的组合来判断系统是否发生低频干扰，若系统没有发生低频干扰，则采用磁罗盘导航方式，若系统发生低频干扰则将系统切换到陀螺仪的导航方式。该方案并未实质性的提高磁罗盘的测量精度，且该导航方案有陀螺仪和多个磁罗盘构成，会导致成本大大增加；王璐、赵忠等的论文《磁罗盘误差分析及补偿》采用ＢＰ神经网络建立误差模型，并利用ＬＭ学习算法训练网络，该方法无须在0 ° ~ 360 °内平均采样，具有神经网络能以任意精度逼近函数的特点，正确设置初始值需要非常小心且易陷入局部最小。

综上所述，目前电子罗盘的标定方法有最小二乘法、椭圆假设法、ＢＰ神经网络法等，这些方法或存在标定步骤较繁琐、对标定所需的一起要求较高或标定精度不够等问题。

为了简化标定步骤、降低对所需仪器的要求以及提高标定精度，本发明涉及了一种电子罗盘的标定方法，该标定方法基于自适应差分进化法和傅里叶神经网络（Adaptibe Differential Ebolution and Fourier Neural Network,ADE-FNN）,通过傅里叶神经网络对电子罗

盘误差建模，该神经网络采用正交傅里叶技术作为网络激发函数，并采用自适应差分进化算法训练网络的权值，得到较为精确的误差模型来补偿罗盘的测量值，从而达到改善罗盘精度的目的。

基于自适应差分进化法和傅里叶神经网络的电子罗盘的标定方法，包括获取蓄念样本、采用傅里叶圣经网络（FNN）简历误差补偿模型以及采用自适应差分进化算法（ADE）训练神经网络权值三大部分，实现的具体步骤如下：

步骤一、获取训练样本；

步骤二、确定神经网络结构；

步骤三、简历电子罗盘误差模型并选择训练指标；

步骤四、根据训练样本采用改进的自适应差分进化算法训练神经网络；

步骤五、将优化后得到的神经网络权值带入神经网络，得到较为精确的补偿模型；

步骤六、将电子罗盘输出的测量值输入神经网络进行补偿，输出补偿后的值。

本发明综合考虑了影响电子罗盘测量精度的因素，提出了基于自适应查分进化法和傅里叶神经网络的标定方法几种对其进行补偿，一方面简化标定的过程，即只需在转台上旋转（无须匀速旋转）电子罗盘一周获取训练样本和对应的真实值；另一方面具有更好的效果，及更精确的抵消外界干扰，提高的量精度。

该补偿方法具有神经网络结构简单、易于实现，同时能以任意净度逼近非线性函数，具有较好泛化能力的优点。

采用正交的傅里叶函数作为神经网络的激发函数，将非线性优化问题转化为线性优化问题，极大地提高收敛速度，避免陷入局部最小。

采用自适应差分进化算法训练神经网络权值，避免了初始值依赖系统先验知识难以选择的问题；同时改进后的差分进化算法在初始阶段有较强的全局搜索能力，能尽可能多地发现可能的全局最优点，而且在后续阶段有较强的局部搜索能力，提高算法收敛速度和求解精度；因此该算法有较强的全局搜索能力，能有效避免过早收敛，而且算法的稳定性好。

如何让一个数字罗盘工作？

电子罗盘作为寻路者使用磁传感器专利技术，第一个提出开发的资料库的公司为美国军方。这项技术被称为“磁感应”，是在罗盘技术自60年前发明磁通门以来，是世界上最大的进步。在磁感应技术对于电子意义不同的地球磁场扰动所造成的外部因素，如铁磁性材料的磁场产生的汽车电气系统。寻路者数字指南针有一个嵌入式微控制器，补偿汽车磁场（扭曲）从地球磁场较强的领域产生一个高度精确的罗盘读数。

罗盘的安装

一个指南针的性能，将在很大程度上取决于其安装位置。指南针依赖于地球磁场提供坐标。任何扭曲的地球磁场的其他来源，如汽车大量铁成分应补偿，以便确定一个准确的坐标。磁源域在任何汽车包括永久磁铁像绝大多数的音响喇叭，电机，电流流动的直流或交流电机，和铁磁性金属，如钢或铁。这些影响干扰源使电子罗盘精度大大降低，指南针放置应远离他们。

有一些领域的影响可以用得到补偿的方式校准指南针确定的位置以避免磁场干扰。然而，它并非总是可能弥补对于随时间变化的领域；例如，干扰所产生的运动的磁性金属，或不可预知的电流在附近的电力线。磁屏蔽可用于大视场的干扰电机或音响喇叭。最好的办法是减少干扰距离。此外，需要附上指南针在磁屏蔽金属壳体。

罗盘倾斜误差

坐标错误由于倾斜很大程度上取决于地理位置。在赤道附近，倾斜误差不那么重要，因为地球的磁场是严格的水平面。这提供了较准的X、Y读数和小的部分修正磁极附近，倾斜误差非常重要—因为有较少的X、Y场合Z分量。倾斜误差也依赖于坐标。

磁场扭曲

附近的有色金属材料是另一个需要考虑的使坐标产生误差的原因。由于坐标是基于对地球的水平场方向的数字罗盘必须是能够衡量这一领域，从其他附近的磁场源或干扰的影响较小。

干扰的量取决于材料内容的平台和连接器以及黑色的物体附近。当一个黑色对象放置在一个统一的磁场扰动它将会产生影响。这个对象可以是钢螺栓或支架指南针或铁附近门锁接近指南针。最终的结果就是一个典型的失真,或异常与地球的磁场是独特的形状的物体。

磁扭曲可以被分类为硬铁和软铁的影响。硬铁扭曲源于永久磁铁和磁化的铁或钢指南针的平台。这些扭曲将保持不变,并在一个固定的位置相对于所有标题的罗盘方位。硬铁效果添加一个常数级字段组件沿着每个轴式传感器的输出。以补偿硬铁扭曲通常是由旋转指南针和平台在一圈和测量的圈上足够的分数来确定这个偏移。一旦发现,(X,Y)抵消可以存储在内存和减去每阅读。最终的结果将是消除硬铁扰动从标题的计算。

软铁扭曲源于交互的地球磁场和任何磁性软材料周围的指南针。像硬铁材料、软金属也扭曲了地球的磁力线。不同的是,数量的失真从软铁取决于指南针方向。

什么是真正的北方？

众所周知,地球的磁极和其转动轴不在同一个地理位置。他们之间的夹角大约为11.5°。这将创建一个区别真正的北方,或网格北,磁北方向或者磁性罗盘会点。只是它是角区别真北磁性和表达为向东或西风带的变化。这种差异的定义为变化角和依赖指南针持续时间短,使磁性罗盘一个有用的导航工具。

指南针校准

每种标定方法相关联的一个指定物理运动指南针的平台以样本周围空间磁场罗盘。软硬铁扭曲将从不同的位置,位置在相同的平台。指南针是永久地安装它的平台,得到一个有效的校准。

一个特定的校准只适用于该位置的指南针。如果指南针是重新定位在同一位置，则需要重新校准。如果需要仅是为了重复性和不准确性也可以使用一个没有任何校准的指南针。