Table of Contents
Advertisement
Quick Links
Advertisement
Table of Contents
Summary of Contents for Lord MicroStrain 3DM-CX5-25
- Page 1 LORD User Manual ® -CX5-25 Attitude and Heading Reference System (AHRS)
- Page 2 , DVRT , EmbedSense , FAS-A , G-Link ® ® ™ ® ® ® ® Little Sensors, Big Ideas. , LORD Microstrain , Live Connect , LXRS , MathEngine , MicroStrain , MIP™, MXRS , Node ® ™ ® ® ®...
-
Page 3: Table Of Contents
® -CX5-25 User Manual Table of Contents System Family Overview Sensor Overview 2.1 Components Basic Setup and Operations 3.1 Software Installation 3.2 System Connections 3.3 Software Interface 3.3.1 Interactive Help Menu 3.4 Sensor Communication 3.5 Sensor Settings 3.5.1 Saving Configurations 3.6 Data Monitoring and Recording 3.7 View Recorded Data 3.8 Interface and Indicators... - Page 4 ® -CX5-25 User Manual 5.3 Magnetometer Auto Calibration 5.3.1 Enable 5.3.2 Capture 5.4 Magnetometer Manual Calibration 5.5 Estimation Filter Aiding 5.6 Heading Aiding Settings 5.6.1 Bias Convergence 5.7 Adaptive Anomaly Rejection 5.7.1 Gravity Adaptive 5.7.2 Mag Adaptive 5.8 Communications Bandwidth 5.9 Platform Frame Transformation 5.10 Estimation Filter Operation 5.11 Estimation Filter Convergence...
- Page 5 ® -CX5-25 User Manual 8.3 Sampling on Start-up 8.4 Connecting to a Datalogger 8.5 Using Wireless Adapters Troubleshooting 9.1 Troubleshooting Guide 9.2 Repair and Calibration 9.3 Maintenance 9.4 Technical Support Parts and Configurations 10.1 Standard Configurations 10.2 Accessories 10.3 Sales Support Specifications 12.1 3DM-CX5 Development Kit Reference Documents...
-
Page 6: System Family Overview
® -CX5-25 User Manual System Family Overview The LORD Sensing 3DM-CX5 family of high-performance, industrial-grade, board-level inertial sensors provides a wide range of triaxial inertial measurements and computed attitude and navigation solutions. In all models, the Inertial Measurement Unit (IMU) includes direct measurement of acceleration and angular rate, and some also offer atmospheric pressure readings. -
Page 7: Sensor Overview
Auto-Adaptive Extended Kalman Filter (EKF) allows the 3DM-CX5-25 to perform well in a wide variety of applications that require low noise, drift, gain, and offset errors. scale factor estimation, and bias estimation outputs are available. -
Page 8: Components
User Manual 2.1 Components The 3DM-CX5-25 Inertial Sensor can be purchased by itself or as part of a Development Kit. All software, drivers, and links to detailed documentation are included with the sensor purchase. For a complete list of available configurations, accessories, additional system products, and ordering... -
Page 9: Basic Setup And Operations
User Manual Basic Setup and Operations To acquire sensor measurements and computed outputs, the 3DM-CX5-25 uses a host computer,an RS232 or USB communications port, and applicable software. The LORD Sensing MIP Monitor software is provided with the system and includes all functions needed for sensor configuration and data acquisition. -
Page 10: Software Installation
User Manual 3.1 Software Installation NOTE The MIP Monitor Software Suite includes hardware drivers required for 3DM-CX5-25 sensor operation. Sensors will not be recognized without these drivers installed. To Install the MIP Monitor software on the host computer, complete the following steps: 1. -
Page 11: System Connections
( see Specifications on page 61 To acquire sensor data the following components are needed: 3DM-CX5-25 sensor, communication cable, power cable (as applicable for RS232 communications) , connectivity board, and a host computer with LORD Sensing MIP Monitor installed. -
Page 12: Software Interface
® -CX5-25 User Manual 3.3 Software Interface The MIP Monitor software includes a main window with system information and menus, a device settings window, and several data monitoring windows. The main window provides an overview of connected devices. Devices are selected by clicking on them. -
Page 13: Sensor Communication
® -CX5-25 User Manual 3.4 Sensor Communication Once power has been applied to the sensor, it is functional. The sensor selects the appropriate serial communication (USB or RS232) on power-up based on which cable is connected. If the hardware drivers have been installed, communication can be established using the MIP Monitor software interface. -
Page 14: Sensor Settings
Device Settings, or select Settings > Device from the main menu. a. Main menu tabs: The main tabs divide the settings into functional groups for the available measurements. For the 3DM-CX5-25 these include calculated measurements (Estimation Fil- ter) and direct inertial sensor measurements (IMU/AHRS). -
Page 15: Saving Configurations
® -CX5-25 User Manual 3.5.1 Saving Configurations Sensor settings are saved temporarily by selecting the OK button in the Device Setup window after configuration, but they are lost when the device is powered off. To save current settings, so they are automatically restored the next time the device is powered on, select Settings >... -
Page 16: Data Monitoring And Recording
® -CX5-25 User Manual 3.6 Data Monitoring and Recording Throughout the MIP Monitor views the same icons are used to control data streaming (sampling) and recording. These icons can be found in the MIP Monitor main window icon toolbar and in each data monitoring window. - Page 17 ® -CX5-25 User Manual Figure 11 - Data Streaming is an example of Sensor Data Monitoring, which displays the selected IMU/AHRS measurements. In data monitoring windows, no data will be displayed until data streaming is started, and no data will be recorded (even if it is being viewed) until data recording is initiated (armed).
-
Page 18: View Recorded Data
® -CX5-25 User Manual 3.7 View Recorded Data Recorded data is stored in either Binary (.bin) or Comma Separated Values (.csv) format, depending on what was selected at the initiation of data recording. The files can be found in the directory specified at that time or in the default directory on the host computer desktop. - Page 19 ® -CX5-25 User Manual 4. To end recording press the Arm Recording button again, and select OK in the confirmation prompt window. 5. Select the Stop Streaming icon to end sampling. 6. Use the red "X" in the upper right of the sensor monitoring window to exit monitoring mode.
-
Page 20: Interface And Indicators
( see Sensor Mounting on page 46 The indicators on the 3DM-CX5-25 include a device status indicator and the device information label. The table below describes the basic status indicator behavior. includes the sensor frame diagram (axis... -
Page 21: Sensor Measurements
User Manual Sensor Measurements The 3DM-CX5-25 block diagram describes its primary hardware components and internal configuration. Integrated Micro-Electro-Mechanical System (MEMS) sensors within the 3DM-CX5-25 are collectively known as the Inertial Measurement Unit (IMU) and include tri- axial gyroscopes (gyros) , tri- axial accelerometers. -
Page 22: Direct Sensor Measurements (Imu Outputs)
® -CX5-25 User Manual 4.1 Direct Sensor Measurements (IMU Outputs) The sensors in an Inertial Navigation System (INS), from which measurements for navigation and orientation are obtained, are collectively known as the Inertial Measurement Unit (IMU). These sensors are arranged on the three primary axes (x, y, and z) to sense angular rate, acceleration, and the local magnetic field. - Page 23 User Manual Table 2 - IMU Measurements lists the IMU measurements available for the 3DM-CX5-25. Additional measurement units may be available in MIP Monitor for some outputs, however they are converted values and do not represent the actual sensor outputs. Only actual output units are listed.
-
Page 24: Computed Outputs (Estimation Filter)
® -CX5-25 User Manual 4.2 Computed Outputs (Estimation Filter) The computed outputs are measurements from the 3DM- CX5- 25 IMU sensors that are blended through an Auto-Adaptive Extended Kalman Filter (EKF) algorithm. The Kalman Filter produces a better estimation of attitude and heading (AHRS) outputs than can be achieved by the inertial sensors individually. - Page 25 ® -CX5-25 User Manual Units Description Measurement indicates the current state of the EF, Filter Status such as running or initializing GPS time corresponding to the cal- GPS Time weeks & seconds culated filter solution Euler angles representation of Attitude orientation expressed as roll, pitch and yaw (Euler RPY) radians...
-
Page 26: Sensor Reference Frames
® -CX5-25 User Manual 4.3 Sensor Reference Frames 4.3.1 Geodetic Frame The World Geodetic System is the standard for cartography and navigation. The latest revision, WGS84, is the reference coordinate system for GPS. It also calculates the magnitude of the local gravity vector using the WGS84 reference formulas. -
Page 27: North East Down (Ned) Frame
® -CX5-25 User Manual 4.3.2 North East Down (NED) Frame The North-East-Down (NED) frame is a local coordinate frame, which is formed by a tangent plane located at a particular point (current coordinates) on the WGS84 reference ellipse. The NED frame is constructed with the (true) North vector along the line of longitude, the East vector along the line of latitude, and the Down vector normal to and towards the tangent plane ( Figure 18 - North East... -
Page 28: Sensor Frame
Device Settings > EF settings > Geographic. Refer to the 3DM-CX5-25 dimensional diagram for the location of the measurement origin ( Sensor Dimensions and Origin on page 1... -
Page 29: Platform Frame
User Manual 4.3.4 Platform Frame The 3DM-CX5-25 includes the option to define an orientation transformationand offset distance from the sensor frame to a user-definable platform frame. This is useful when the sensor cannot be mounted in the same location or orientation as the desired reference point on the platform frame. - Page 30 ® -CX5-25 User Manual Figure 21 -Platform Frame Settings The orientation transformation affects the following EF outputs: attitude, position, linear and compensated acceleration, compensated angular rate, and gravity vector. It also affects the following IMU outputs: acceleration, angular rate, magnetic field vector, delta Theta, and delta velocity ( see Computed Outputs (Estimation Filter) on page 24 Transformed acceleration is expressed at the location of the sensor but within the platform frame.
-
Page 31: Performance Optimization
® -CX5-25 User Manual Performance Optimization 5.1 Gyroscope Bias Gyroscope biases (offsets) can be zeroed out to set a baseline value for the static home position and conditions in the application. This should be done after sensor installation. To set the gyroscope baseline, place the sensor or sensor platform in the desired home position. Allow 2-3 minutes for the sensor to warm up and for the temperature to stabilize for the best bias capture. -
Page 32: Tare Mounting Pitch-Roll
® -CX5-25 User Manual 5.2 Tare Mounting Pitch-Roll This function captures the current pitch-roll orientation of the device and sets it as the level reference, providing a convenient way to set the sensor to vehicle frame transformation. For more information on the corresponding LORD Sensing MIP Data Communications Protocol (DCP) command, see the DCP Manual . -
Page 33: Magnetometer Auto Calibration
® -CX5-25 User Manual 5.3 Magnetometer Auto Calibration 5.3.1 Enable Enabling the EF Mag Hard Iron Auto Calibration allows estimation of the magnetometer bias (bias tracking) for purposes of auto- calibration. Enabling the EF Mag Soft Auto Calibration allows estimation of the magnetometer scale factor (scale factor tracking) for purposes of auto-calibration. To enable, select the sensor name in the MIP Monitor software main window, then select Settings >... -
Page 34: Capture
® -CX5-25 User Manual 5.3.2 Capture This command captures the current value of the auto-calibration, applies it to the current fixed hard and soft iron calibration coefficients, and replaces the current fixed hard and soft iron calibration coefficients with the new values. This may be used in place of (or in addition to) a manual hard and soft iron calibration ( see Magnetometer Manual Calibration on page 35 ) utility such as the LORD... -
Page 35: Magnetometer Manual Calibration
However, often these sources are hard to avoid or are hidden. To mitigate this effect when using the 3DM-CX5-25 magnetometer to aid in heading estimations, a field calibration of the magnetometer after final installation is highly recommended. This can be accomplished using LORD Sensing MIP Hard and Soft Iron Calibration software. ... - Page 36 ® -CX5-25 User Manual 3. The sensor should automatically appear in the sensor list. If not, use the Refresh button Figure 26 - Sensor Menu to query it and then select the sensor ( ). 4. Select the Arm Recording button next to Collect Data. The software will begin taking readings, as indicated by the points counter in the graphing window.
- Page 37 ® -CX5-25 User Manual the best choice. If there are enough points in all dimensions, the Ellipsoid Fit may be better. Generally, if the Spherical and Ellipsoid Fits are close in the mean diameter, then the Ellipsoid Fit will be the best choice. 7.
-
Page 38: Estimation Filter Aiding
® -CX5-25 User Manual 5.5 Estimation Filter Aiding There are two categories to customize heading and pitch-roll. To enter the Estimation Filter Aiding menu, select the sensor name in the MIP Monitor software main window, then select Settings > Device > Estimation Filter > EF Aiding. 1. -
Page 39: Heading Aiding Settings
5.6 Heading Aiding Settings Device settings are stored in the sensor memory. Only the configuration options that are available for the type of sensor being used are displayed in the configurations menus. The 3DM-CX5-25 has two heading options. If the setting is none, the estimated heading will drift when little-or-no changes in velocity are sensed (e.g. -
Page 40: Bias Convergence
® -CX5-25 User Manual 5.6.1 Bias Convergence Accurate estimation of the biases can take several minutes to converge, therefore after the filter is initialized, the free-inertial performance will continue to improve until the bias estimations settles. The MEMS sensor manufacturers quote bias drift stability numbers which correspond to the expected drift in bias while the sensor is operating. -
Page 41: Mag Adaptive
® -CX5-25 User Manual 5.7.2 Mag Adaptive Enabling this feature will allow the filter to reject magnetometer readings when the magnitude error exceeds the high limit (in m/s ^ 2). The bandwidth (in Hz) sets the cutoff frequency of the low pass see Communications Bandwidth on page 42 filter applied to the magnetometer error ( ). -
Page 42: Communications Bandwidth
Overrunning the communication bandwidth will result in dropped data packets. Most computer RS232 ports are limited to 115,200 baud even though the 3DM-CX5-25 is capable of running at 921,600 baud. 5.9 Platform Frame Transformation... -
Page 43: Estimation Filter Convergence
5.11.2 Output Uncertainty The 3DM-CX5-25 estimation data set includes a filter status field that contains a set of status flags. These flags pertain to high covariance values for attitude and inertial sensor parameters. These flags should be monitored and cross-checked against the corresponding uncertainty fields when they appear. -
Page 44: Vibration Isolation
5.13 IMU Sensor Calibration All of the internal sensors in the 3DM-CX5-25 are calibrated when the device is manufactured, and the calibration values are saved in the device memory. With the exception of the magnetometer field... -
Page 45: Import And Export Settings
® -CX5-25 User Manual 6.1 Import and Export Settings The import and export settings features provide a consolidated file of the user settings, enabling Device Settings information to be saved and shared. For example, exporting settings to the LORD technical support team helps facilitate fast and accurate resolution of technical issues. -
Page 46: Sensor Installation
® -CX5-25 User Manual Sensor Installation 7.1 Sensor Mounting See the CX5 Interface Control Document for detailed drawings and mounting instructions. The sensor has three holes for fastening to ensure maximum stability. Mounting fasteners should be 2- 56 x ½" button head screws, either brass or 300 series stainless steel. The sensor can be mounted in any orientation, as required for the application. -
Page 47: System Integration
The C-Series Connectivity Board may be used as a standalone interface or may be used as a reference design for embedding the 3DM-CX5-25 in the user's application. For detailed C- Series connectivity board reference design documentation, see Reference Design Documentation on the LORD Sensing website. -
Page 48: Packet Builder
8.1.1 Packet Builder To expedite program development, a packet builder tool is included in the MIP Monitor software. The packet builder allows users to send multiple packets to the 3DM-CX5-25 and view the resulting reply data. Applicable protocol structure and design is described in the 3DM-CX5-25 LORD Sensing MIP Data Communications Protocol (DCP) Manual. -
Page 49: Sensor Direct Mode
® -CX5-25 User Manual 8.1.2 Sensor Direct Mode The MIP Monitor software can be used to put the sensor in a mode that allows direct programmatic access to the internal Inertial Measurement Unit (IMU). The IMU has its own processor and protocol commands and native data outputs from the individual IMU sensors that may not be available in MIP Monitor. -
Page 50: Sensor Wiring
Logic Level GPIO Logic Level Disable Disable (Open or Low = Enable) Mounting Holes Chassis Chassis Ground * USB is not available on the 3DM-CX5-25 and may be left connected to USB or unconnected. Figure 36 -Pin Locations and Functions... -
Page 51: Sampling On Start-Up
® -CX5-25 User Manual 8.3 Sampling on Start-up The Save Current Settings command can be used to instruct the sensor to start streaming data as soon as it powered on. This can be useful in sensor integration applications in which immediate data acquisition is desired, and connection to MIP Monitor for data logging is not required. -
Page 52: Connecting To A Datalogger
® -CX5-25 User Manual 8.4 Connecting to a Datalogger Many inertial applications incorporate dataloggers of all different types to collect and distribute sensor outputs. For more information and examples refer to the "Using Dataloggers with Inertial Sensors" Technical Note on the LORD Sensing website, or contact LORD Sensing Technical Support ( Technical Support on page 57 8.5 Using Wireless Adapters In some applications it can be very useful to set up wireless communications between the sensor to the... -
Page 53: Troubleshooting
® -CX5-25 User Manual Troubleshooting 9.1 Troubleshooting Guide... - Page 54 ® -CX5-25 User Manual Problem Possible cause and recommended solution 1.1 no power is applied The status indicator on the device will be off. Make sure the 1. POWER sensor is connected to a power source and the status indicator illuminates.
- Page 55 ® -CX5-25 User Manual Problem Possible cause and recommended solution Sensing for reconfiguration. 2.5 sensor or cables are damaged Verify all connections, power, and settings. If available, try installing an alternate cable or sensor one at a time to see if the faulty device can be identified. ...
-
Page 56: Repair And Calibration
® -CX5-25 User Manual 9.2 Repair and Calibration General Instructions In order to return any LORD Sensing product, you must contact LORD Sensing Sales or Technical Support to obtain a Return Merchandise Authorization (RMA) number. All returned merchandise must be in the original packaging, including manuals, accessories, cables, etc. -
Page 57: Maintenance
® -CX5-25 User Manual 9.3 Maintenance There are no user- serviceable parts on the 3DM - CX5 - 25. Removing the device cover or disassembling in any way voids the product warranty. 9.4 Technical Support There are many resources for product support found on the LORD Sensing website including technical notes, FAQs, and product manuals. -
Page 58: Parts And Configurations
® -CX5-25 User Manual Parts and Configurations 10.1 Standard Configurations For the most current product information, custom, and OEM options not listed below, refer to the LORD Sensing website or contact the LORD Sensing Sales Department. Table 4 - Model Numbers describes the standard models available at the time this manual was published. - Page 59 ® -CX5-25 User Manual The same options are available in each model, and are indicated in the last four digits of the product part number. For a list of the starter kit contents,( see Components on page 1 Figure 38 -Standard Part Numbers...
-
Page 60: Accessories
® -CX5-25 User Manual 10.2 Accessories The following parts are available for use with the 3DM - CX5 - 25. For the most current product information refer to the LORD Sensing website or contact the Sales Department. ( see Sales Support on page 60 ). -
Page 61: Specifications
® -CX5-25 User Manual Specifications General Integrated Triaxial accelerometer, triaxial gyroscope, triaxial sensors magnetometer, and temperature sensors, Inertial Measurement Unit (IMU) outputs: acceleration, angular rate, magnetic field, ambient pressure, Delta-theta, Delta-velocity Computed outputs Extended Kalman Filter (EKF): filter status, timestamp, attitude estimates (in Euler angles, quaternion, orientation Data outputs matrix), linear and compensated acceleration, bias... - Page 62 ® -CX5-25 User Manual Computed Outputs EKF outputs: ±0.25° RMS roll and pitch, ±0.8° RMS heading (typ) Attitude accuracy CF outputs: ±0.5° RMS roll and pitch, ±1.5° RMS heading (typ) Attitude heading range 360° about all axes Attitude resolution < 0.01° Attitude repeatability 0.2°...
-
Page 63: 3Dm-Cx5 Development Kit
® -CX5-25 User Manual 12.1 3DM-CX5 Development Kit See the 3DM- CX5 Reference Design Documentation for detailed drawings and notes on the components included in the development kit. Figure 39 -C-Series Connectivity Board... -
Page 64: Reference Documents
Many references are available on the LORD Sensing website including product user manuals, technical notes, and quick start guides. These documents are continuously updated and may provide more accurate information than printed or file copies. Document Where to find it 3DM-CX5-25 http://www.microstrain.com/documents/inertial support documentation NIST Calibration Procedures http://www.nist.gov/calibrations/ http://www.astm.org/Standard/standards-and-... -
Page 65: Glossary
® -CX5-25 User Manual Glossary A/D Value The digital representation of analog voltages in an analog-to-digital (A/D) conversion. The accuracy of the conversion is dependent on the resolution of the system electronics. Higher resolution produces a more accurate conversion. Acceleration In physics,acceleration is the change in the rate of speed (velocity) of an object over time. - Page 66 ® -CX5-25 User Manual ASTM (Association of Standards and Testing) a nationally accepted organization for the testing and calibration of technological devices Attitude the orientaion of an object in space with reference to a defined frame, such as the North-East-Down (NED) frame Azimuth A horizontal arc measured between a fixed point (such as true north) and the vertical circle passing...
- Page 67 ® -CX5-25 User Manual Delta-Theta the time integral of angular rate expressed with refernce to the device local coordinate system, in units of radians Delta-velocity the time integral of velocity expressed with refernce to the device local coordinate system, in units of g*second where g is the standard gravitational constant ECEF (Earth Centered Earth Fixed) a reference frame that is fixed to the earth at the center of the earth and turning about earth's axis in the...
- Page 68 ® -CX5-25 User Manual Host (computer) The host computer is the computer that orchestrates command and control of attached devices or net- works. Inertial Measurement System Inclinometer device used to measure tilt, or tilt and roll Inertial pertaining to systems that have inertia or are used to measure changes in inertia as in angular or linear accelerations INS (Inertial Navigation System) systems that use inertial measurements exclusively to determine position, velocity, and attitude, given...
- Page 69 ® -CX5-25 User Manual NED (North-East-Down) A geographic reference system acronym for Original Equipment Manufacturer Offset A non-zero output signal of a sensor when no load is applied to it, typically due to sensor imperfections. Also called bias. Orientation The orientaion of an object in space with reference to a defined frame. Also called attitude. Pitch In navigation pitch is what occurs when vertical force is applied at a distance forward or aft from the cen- ter of gravity of the platform, causing it to move up or down with respect to the sensor or platform frame...
- Page 70 ® -CX5-25 User Manual acronym for Root Mean Squared Roll In navigation roll is what occurs when a horizontal force is applied at a distance right or left from the cen- ter of gravity of the platform, causing it to move side to side with respect to the sensor or platform frame origin.
- Page 71 ® -CX5-25 User Manual UTC (Coordinated Universal Time) The primary time standard for world clocks and time. It is similar to Greenwich Mean Time (GMT). Vector a measurement with direction and magnitude with refernce from one point in space to another Velocity The rate of change of position with respect to time.