Attitude and Heading Reference Systems

Transcription

1 Attitude and Heading Reference Systems FY-AHRS-2000B Installation Instructions V1.0 Guilin FeiYu Electronic Technology Co., Ltd Addr: Rm. B305,Innovation Building, Information Industry Park,ChaoYang Road,Qi Xing District,Guilin China Website:

2 Dear customers: Hello! Thank you for using the products of Guilin Feiyu Electronic Technology Co, Ltd. Please carefully read the instructions to ensure the proper use and operation. 1

3 FY-AHRS-2000B Installation Instructions FY-AHRS-2000B is a high-performance strap down inertial navigation system that can measure any point of orientation of the entire locomotive and vehicle in the 3D space. AHRS could make high-precision positioning for any stationary or moving objects with angular velocity, even short magnetic interference will not affect the heading accuracy of the AHRS. The system can be carried out AHRS magnetic field calibration, to eliminate the hard and soft iron materials motorcycles offset caused by magnetic fields. Features: 1 Using high-performance all solid-state three-axis accelerometer, three-axis angular rate sensors and three-axis magnetic field sensor. 2 Three axis 360-degree all-dimensional output of the attitude and heading, attitude and heading data on a static accuracy of less than 0.5 degrees, the dynamic accuracy of less than 2 degrees. 3 Built-in sensor auto-calibrate, can automatically compensate for the interference of temperature drift, noise, external magnetic field, etc. 4 Super long time stability and fast dynamic response. Application: Ground Transportation Robots Aircraft Video Camera ect. The AHRS includes three gyroscopes, three accelerometers and three magnetic field meters. Real-time measure three axial angular velocity, acceleration, and magnetic field strength. After the processing by the internal microprocessor, the AHRS outputs drift-free attitude and heading information, the three-dimensional acceleration, three-dimensional angular velocity, three-dimensional geomagnetic field, which have been compared and checked-off. 2

4 1. Dimensions and Interface Description: Dimensions: length(mm) width(mm) height(mm) Interface: Black cable Red cable Yellow cable Green cable GND +5V RX TX 2. Performance Parameter Specification FY-AHRS-2000B Remark Performance Refresh Rate(Hz) 1~100 The default refresh rate is 20Hz Initialization Time(sec) 3 Heading Output Range(deg) 0~360 3

5 Accuracy(deg) ±1 Compensation and Correction Resolution(deg) 0.1 Attitude Roll output range(deg) ±180 Pitch output range(deg) ±90 Static Accuracy(deg) <0.5 Dynamic Accuracy(deg RMS) <2 Resolution(deg) 0.05 Angular velocity Roll, Pitch,Heading(deg/sec) <2000 Optional range of different Resolution(deg/sec) <0.05 Bandwidth(Hz) 100 Linear Acceleration X, Y, Z axis measuring range(g) ±3 Deviation(mg RMS) 0.3 Bandwidth(Hz) 40 Magnetic field X, Y, Z axis measuring range(gauss) ±1.5 Output range -2048~ MG/LSB Bandwidth(Hz) 20 Environmental Indicators Working temperature( ) -40~+70 Electrical indicators Input Voltage(V) 3.3V~6V Recommended 5V Input Current(mA) Digital Output <80 TTL or RS232 (Optional) Baud rate of output 4800~ The default baud rate is Physical index Size(mm) Length width height Weight(g) 18 4

6 3 Hardware Installation FY-AHRS-2000B Installation Instructions FY-AHRS-2000B should be installed on a stable platform; the installation of the surface should be parallel with the ground as far as possible when still placed on the platform, and keep it away from the magnetic field effects as far as possible. Magnetic objects must avoid being included. For example: car engines, electric motors, audio speakers, steel, iron and steel nuts or bolts. We recommend using copper, plastic or aluminum as the FY-AHRS-2000B installation and packaging materials. Because it equipped with a gyro and acceleration sensor, so we must fix it on the platform cautiously. When install FY-AHRS-2000B, make ensure that the "forward" on the shell (it means the positive X-axis) keep the same direction with the platform move forward straight. This is very important. Once the installation is finished, you d better make ensure that no more change in use. Since magnetic interference may exist in the surroundings, for realize the correction of course, we advised that please run the magnetic field compensate program of the FY-AHRS-2000B after each time the environment changed.we must select the install position carefully when install the FY-AHRS-2000B.The selected position should expose the electronic component fully to the Earth's magnetic field, while keep it relatively isolated from the magnetic field effects and interference. FY-AHRS-2000B includes gyroscopes and accelerometers, in order to initialize the sensors, you should keep it horizontal and static for about 3 to 5 seconds when Power-on. If you power-on it during movement, it may cause the attitude data accuracy decline. If the external environment changed so much, when boot and maintain the stationary state, the gyroscope angular rate is greater than 1 per second, please perform "configuration" - "" gyro to initialize ". 4 Power and Signal Connections FY-AHRS-2000B connects to the user equipment through standard TTL serial protocol, so if you are using a notebook computer, please prepare a USB-serial converter. FY-AHRS-2000B factory default serial port baud rate is 19200, the output data refresh rate is 20Hz. Recommended operating voltage is 5V DC power input. The voltage input range is 3.3V ~ 6V, if the supply voltage is out of the range, the AHRS will be damaged or caused performance reduction. 5 Demo Software Installation and Use The demo software program's document of FY-AHRS-2000B is AHRS test software.exe, after completing the installation, the interface is as follows: 5

7 Select the serial port used to connect in the "Port" field, such as: "COM1"; in the "Rate" field select the baud rate as "19200"; FY-AHRS-2000B connected to the default wave special rate of 19200, a start-byte, 8 data bytes, a Stop byte, no parity, either hardware or software no "handshake." Baud rate can be changed by command. Click "Open Serial Port" button, if the FY-AHRS-2000B has been powered on and in working status, you will see the attitude, angular rate and other parameters displayed on the left window. After click "Graphic Demo" button, the 3D graphics demo window will be pop-up. 6

8 The three-dimensional rectangular in the demo program will change its attitude accordingly thought the change attitude of the FY-AHRS-2000B. Select the menu "Show" - electronic compass display ", you can switch to two dimensions compass view, it will indicating the real time course. 7

9 At the main interface of AHRS testing software, you can configure the output serial baud rate, the output data refresh rate, the output data content, etc, and you also can set the baseline calibration and the magnetic field calibration of the sensors inside the FY-AHRS-2000B. 6 Magnetic field calibration FY-AHRS-2000B will be started magnetic compensation calibration procedures once the installation finished. The magnetic field compensation process in the module's firmware determines the magnetic field calibration impact of the installation of platform, so even if the FY-AHRS-2000B is installed on the steel device (for example, a vehicle), it still can provide accurate readings. FY-AHRS-2000B has the compensation effect only in a limited interference range. Range value of magnetometer is between minus 100 and plus 100 m-teslas which is approximately twice the magnetic force in middle latitude northern hemisphere, If the disturbance value of the magnetic field more than plus or minus 50 m-teslas, the magnetometer could reach saturation and block compensation. Magnetic compensation function is semi-automatic. Once started, FY-AHRS-2000B will collect data automatically from every position of the circumference. After completing this work, the module will calculate the correction factor to compensate for the near magnetic field abnormalities, and to store the corrected value in the permanent memory. After the compensation process, the corrected value will be merged into the subsequent azimuth data. 8

10 If necessary, the compensation process can be repeated several times. When began to run the test program, please note: The magnetic objects (such as the nearby mobile phones, structural steel and buried underground pipelines) may lead to azimuth errors. If the FY-AHRS-2000B is installed in a vehicle, it will encounter the magnetic field anomaly; this is why there is a magnetic compensation procedure. However, for some bulky magnetic properties are very likely to distort the earth s magnetic field, even the process of magnetic compensation happened in a long distance. Magnetic declination and bias of installation is the most important parameter values, which can be entered into the module by the host. Usually, when power-on, the module will automatically set the value of magnetic declination and bias to 0. This can be changed through software commands, and the value is still valid after restarted. Magnetic declination (also known as magnetic variable) is the angle between true north and magnetic north. Azimuth bias is defined as the level angle deviation between the module's forward axis (X axis) and the reference axis of installation platforms. Azimuth bias is a constant, which is decided the module mechanical placement and installation elements. Magnetic declination and Azimuth bias will affect the accuracy of the Azimuth observation. The module should use these two corrected values, and add it to the magnetic field course deviation angle correction option. According to usual practice, both the mark symbol of magnetic declination and azimuth bias used in the east are belonging to positive sign. For example, if magnetic north is the east of true north, magnetic declination is positive. For example, the local magnetic declination is -6, the install bias is -2, and then the magnetic field course deviation angle correction option should fill in the 8. Choosing menu "configuration"-> "magnetic calibration procedures", the magnetic compensation procedures will be start, at the same time, the process and longitude of the program operation would be shown on the bottom of the main procedures information displayed window. Magnetic compensation is used to confirm the magnetic attribute of surrounding environment, and obtaining the factor which is used to compensate the magnetic. If lack of this amended procedure, the substantial azimuth angle error may occur. In the implementation of the "Start calibration of XY-axis magnetic field", you need to place FY-AHRS-2000B horizontally (the X-Y plane of FY-AHRS-2000B is parallel with the ground level. At the same time, the right side of Z-axis being faced down with the ground water level vertically), and rotate the module clockwise, keep it stable circular movement. If the FY-AHRS-2000B is installed in a vehicle, the above steps are completed by rotate the vehicles slowly on the horizontal ground. 9

11 The magnetic field calibration process will show the current rotation angle by drawing the circle. You must clockwise rotate FY-AHRS-2000B continuously until the end of the amendment. If the drawn circumference is significantly distortion, it may be coursed by the overlarge external magnetic interference or there are problems in the process of rotation, so you must re-calibrate. By the end of the magnetic field calibration, click "Write FLASH button, it will write the amend parameters in the FLASH and keep them permanently. At the same installation platform, if the external environment is not change too much, one time amendment will be enough. FY-AHRS-2000B Interface Protocol FY-AHRS-2000B Data output format description (standard RS-232, TTL, ASCII character output): Command head, field1, field 2, field 3,, the field n * checksum field (CRLF) Between the fields with "," separated, each with a carriage return line feed end of the data. FY-AHRS-2000B attitude data format 10

12 Command Command Field 1 field 2 field 3 field 4 field 5 field 6 type head attitude data $FYZT Pitch Roll heading X angular rate Y angular rate Z angular rate field 7 field 8 field 9 field 10 field 11 field 12 field 13 Check X acceleration Y acceleration Z acceleration resultant acceleration X magnetic field Y magnetic field Z magnetic field * Check value FY-AHRS-2000B attitude data output example: $FYZT,-0.92,-0.60,341.77,-0.15,0.14,0.11,0.02,-0.01,1.00,1.00,447.19,140.02,159.50*F4 Check value calculation method: arithmetic accumulate all data by-byte start from each "$" of the data symbols (including the $) to the"*" (excluding * ). FY-AHRS-2000B Configuration Format Description (standard RS-232,TTL, ASCII character input): Command head, command NO, parameter1, parameter2,,parameter n (CRLF). Between the fields with "," separated, with a carriage return line feed end of each data. Command type Configure the output refresh rate Configure the output baudrate Command head Command NO Parameter 1 $Config 6 Refresh rate settings, Parameter setting range , 100Hz 2, 50Hz 5, 20Hz 10, 10Hz 100,1Hz $Config 7 Baudrate settings, Parameter setting range 0 7 Parameter 2 parameter 3 parameter 4 NULL NULL NULL NULL NULL NULL 11

13 Configure magnetic declination Open/Close the FY-AHRS-200 0B serial data output magnetic field calibration 0,4800 1,9600 2, , , , , , $Config 4 Setting of the magnetic declination, Parameter setting range For setting the magnetic deviation angle and installed heading bias $Config 9 Parameter setting range 0 1 0,close 1,open $Config 10 The magnetic field calibration options 1 2 1,Start calibration XY-axis magnetic field 2,Reserved. After sending this command, you must clockwise rotate FY-AHRS-2000B horizontally to complete the magnetic field NULL NULL NULL NULL NULL NULL NULL NULL NULL 12

14 calibration write the configuration information in the FLASH $Config 99 It is fixed at 1 Once configured, send this command to write the configuration information in the FLASH NULL NULL NULL FY-AHRS-2000B attitude configure command example: $Config,9,1 (CRLF) Open the FY-AHRS-2000B serial data output $Config,4,16 (CRLF) Configure the FY-AHRS-2000B magnetic field deviation angle of 16 degrees. $Config,99,1(CRLF) Write the configuration information to the FLASH. Attention: If there is any change of the configuration parameters, you must click "Write FLASH" button, or choose menu "configuration"->"permanent preserve configuration parameters", to write the configuration to FLASH and permanent preserve, or next time power up, these configuration parameter will be lost END Note: We reserve the right to change this manual at any time! And the newest edition will be shown on our website. 13