Welcome to the training module on Analog Device’s ADIS1636X iSensor® IMUs. This training module introduces a complete triple axis gyroscope and triple axis accelerometer inertial sensing device.
Gyroscopes are used to measure angular rate.. that is… how quickly an object turns. The rotation is typically measured in reference to one of three axis: yaw, pitch, or roll. The diagram represents each axis of sensitivity relative to a package mounted to a flat surface. Depending on how a gyro normally sits, its primary axis of sensitivity can be one of the three axis of motion… again… yaw, pitch, or roll. The gyroscope can also be used to measure change of inclination or change of direction by the inte-gration of angular rate. The gyro would output a voltage proportional to the angular rate, as determined by its sensitivity, measured in millivolts-per-degree-per-second (mV/ ° /s).
The ADIS16360/ADIS16365 iSensor provides complete tri-axis inertial sensing (both angular and linear motion) in a compact module fully ready for system integration. With Analog Devices’ iMEMS sensor technology at its core, the sensor includes embedded processing for sensor calibration and tuning. A SPI interface allows for simple system interfacing and programming. The SPI port provides access to the following embedded sensors: x-, y-, and z-axis angular rate; x-, y-, and z-axis linear acceleration; internal temperature; power supply; and an auxiliary analog input. The internal sensors are calibrated, cross compensated, and precision aligned to correct for all significant electrical, positional, and motion influences. Other options are now available including the ADIS16364 with a 5g accelerometer core, and the ADIS16362 with a 1.7g core; Both of these options also allow cost optimizations via a limited temperature calibration range of -20 to 70C.
The ADIS16360/ADIS16365 inte-grate three orthogonal axis of gyroscope sensors with three orthogonal axes of accelerometer sensors, creating the basic six degrees of freedom (6DOF) in a single package. The accelerometers are oriented along the axis of rotation for each gyroscope. These six sensing elements are held together by a mechanical structure that provides tight force & motion coupling, as well as excellent x, y, z orthogonality to within 0.05 degrees. Each sensor’s output signal is sampled using an A/D converter. The digital data is then fed into a proprietary digital processing circuit. The digital processing circuit applies the correction tables to each sensor output, manages the input/ output function using a simple register structure and SPI serial interface, and provides many other features that simplify system level designs. For applications requiring the use of magne-tometers for long term stability, the ADIS16405 is also available. The ADIS16405 includes a tri-axis magnetometer along with the 3-axis gyro and accelerometer, in the same package and with the same interface as the ADIS16365.
The ADIS16360/ADIS16365 iSensor allows industrial designers for the first time to equip their systems with sophisticated motion analysis and navigational dead reckoning functions previously reserved for defense, aerospace, and other high-end applications, at approximately one tenth of the cost. By detecting tiny shifts in linear acceleration and angular movement, the sensor provides dead reckoning, allowing vehicles to remain on course until a lost GPS signal is restored. In addition to navigation, the sensor can be used in highly sensitive robotic and other motion control devices, where the inertial measurement unit (IMU) helps make certain that precision movements can be accurately repeated thousands of times. For instance, the ADIS16365 helps stabilize an aerial camera in motion picture production; controls a robotic arm in factory automation; and ensures stability in a prosthetic limb.
The core MEMs angular rate sensor or gyroscope operates on the principle of a resonator gyroscope. Two poly-silicon sensing structures each contain a dither frame, which is electro-statically driven to resonance. This provides the velocity element required to produce a Coriolis force during rotation. At two of the outer extremes of each frame, orthogonal to the dither motion, are movable fingers that are placed between fixed fingers to form a capacitive pickoff structure that senses Coriolis motion. The resulting signal is fed to a series of gain and demodulation stages that produce the electrical rate signal output.
The ADIS16360 provides a factory calibration that simplifies the process of integrating it into system-level designs. This calibration provides correction for initial sensor bias and sensitivity, power supply variation, axial alignment, and linear acceleration (gyroscopes). An extensive, three-dimensional characterization provides the basis for generating correction tables for each individual sensor. The ADIS16365 provides the same calibration, over temperature.
The serial peripheral interface (SPI) port includes four signals: chip select (CS), serial clock (SCLK), data input (DIN), and data output (DOUT). The CS line enables the SPI port and frames each SPI event. When this signal is high, the D-OUT line is in a high impedance state and the signals on D-IN and S-CLK have no impact on operation. A complete data frame contains 16 clock cycles. Because the SPI port operates in full-duplex mode, it supports simultaneous, 16-bit receive (DIN) and transmit (DOUT) functions during the same data frame. This enables the user to configure the next read cycle, while, at the same time, receiving the data associated with the previous configuration.
The output data registers are starting with the most significant bit or MSB of the upper byte. Each has the following bit sequence: new data or ND flag, error/alarm or EA flag, followed by 14 data bits. The data bits are least significant bit justified and, in the case of the 12-bit data formats, the remaining two bits (Bit 12 and Bit 13) are not used. The ND flag indicates that unread data resides in the output data registers. This flag clears and returns to 0 during an output register read sequence. It returns to 1 after the next internal sample update cycle completes. The EA flag indicates an error condition.
There are many programmable features that are controlled by writing commands to the appropriate control registers using the SPI port. The ADIS16360/ADIS16365 uses a temporary, RAM-based memory structure to facilitate the control registers. The operational configuration is stored in a flash memory structure that automatically loads into the control registers during the start-up sequence. Each nonvolatile register has a corresponding flash memory location for storing the latest configuration contents.
Installation requires two steps: mechanical attachment of the body, followed by the electrical connection. This device is designed for post-solder reflow installation.
All iSensor products, including the ADIS1636X, are supported by the ADIS-USBZ Evaluation Platform and software tool set. The ADIS16365BCCZ and ADIS16360BCCZ plug directly into the ADISUSBZ board, as shown. Also available for simple prototyping are the ADIS16360/PCBZ and ADIS16365/PCBZ which include a simple I/O board connector translation, bringing the ADIS1636X interface to I/O headers.
Thank you for taking the time to view this presentation on “ ADIS1636X iSensor® IMUs” . If you would like to learn more or go on to purchase some of these devices, you may either click on the part list link, or simply call our sales hotline. For more technical information you may either visit the Analog Devices site – link shown – or if you would prefer to speak to someone live, please call our hotline number, or even use our ‘live chat’ online facility.
ADIS1636X iSensor® IMUs
ADIS1636X i Sensor® IMUs <ul><li>Source: ANALOG DEVICES </li></ul>
Applications <ul><li>Guidance and control </li></ul><ul><li>Platform control and stabilization </li></ul><ul><li>Motion control and analysis </li></ul><ul><li>Inertial measurement units </li></ul><ul><li>General navigation </li></ul><ul><li>Image stabilization </li></ul><ul><li>Robotics </li></ul>
Gyroscope Sensor <ul><li>The core MEMS angular rate sensor (gyroscope) operates on the principle of a resonator gyroscope. </li></ul><ul><li>The dither frame provides the velocity element required to produce a Coriolis force during rotation. </li></ul><ul><li>At two of the outer extremes of each frame, orthogonal to the dither motion, movable fingers sense the Coriolis motion. </li></ul>
<ul><li>Writing to Registers </li></ul><ul><ul><li>Two data frames are required when writing the entire 16-bit space of a register. </li></ul></ul><ul><ul><li>16 SCLK cycles are required for a successful write operation. </li></ul></ul><ul><li>Reading from Registers </li></ul><ul><ul><li>A single read command requires two separate data frames </li></ul></ul>SPI Interface
Data Registers <ul><li>Configuration of Output Data Registers </li></ul><ul><li>Output Data Register s </li></ul>New data flag Error/Alarm flag data bits Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Bit8 Bit9 Bit10 Bit11 Bit12 Bit13 EA ND
Control Registers <ul><li>A temporary, RAM-based memory structure is used to facilitate the control registers. </li></ul><ul><li>The following features are programmable by control registers: </li></ul><ul><ul><li>Calibration: bias level control for all six sensors </li></ul></ul><ul><ul><li>Global commands: single-write initiations for common operations </li></ul></ul><ul><ul><li>Operational control </li></ul></ul><ul><ul><ul><li>Sample rate : defines how often data output variables are updated </li></ul></ul></ul><ul><ul><ul><li>Power management : provides a programmable shutdown period </li></ul></ul></ul><ul><ul><ul><li>Digital filtering : provides additional noise reduction on all of the output data registers </li></ul></ul></ul><ul><ul><ul><li>Dynamic range : dynamic range settings </li></ul></ul></ul><ul><ul><ul><li>DAC output : controls the operation of 12-bit level adjustment. </li></ul></ul></ul><ul><ul><ul><li>Digital input/output : establishes the configuration of GPIO pins and handles the SPI-to-pin controls </li></ul></ul></ul><ul><ul><li>Operational status and diagnostics </li></ul></ul><ul><ul><ul><li>Self-test : verifies the mechanical integrity of the MEMS sensor </li></ul></ul></ul><ul><ul><ul><li>Status conditions : checks error condition </li></ul></ul></ul><ul><ul><ul><li>Alarms : monitors two independent alarms </li></ul></ul></ul>
Installation Guidelines <ul><li>Mechanical Attachment </li></ul><ul><ul><li>The open mounting tabs on each side of the body provide enough room for 2 mm (or 2-56) machine screws. </li></ul></ul><ul><ul><li>316 stainless steel and aluminum screws can be used for this attachment. </li></ul></ul><ul><li>Electrical Connections </li></ul><ul><ul><li>The electrical interface is a single connector that is attached to a flexible circuit extension. </li></ul></ul><ul><ul><li>One option for mating connectors can be found in the Samtec CLM family. </li></ul></ul>1.588mm hole and slot for alignment pins, 2 each Drill and tap hole for 2mm (2-56) screw, 2 each
Evaluation Board <ul><li>SPI-to-USB Interface </li></ul><ul><ul><li>ADISUSBZ </li></ul></ul><ul><li>i Sensor™ Evaluation Software </li></ul><ul><ul><li>Device control </li></ul></ul><ul><ul><li>Data plots, data logging </li></ul></ul>
Additional Resource <ul><li>For ordering ADIS16360/ADIS16365, please click the part list or </li></ul><ul><li>Call our sales hotline </li></ul><ul><li>For more product information go to </li></ul><ul><ul><li>http://www.analog.com/adis16360/ </li></ul></ul><ul><ul><li>http://www.analog.com/adis16365/ </li></ul></ul><ul><li>For additional inquires contact our technical service hotline or even use our “Live Technical Chat” online facility </li></ul>