CTR Electronics Pigeon 2.0, User Manual

Page 1: ...e ___ www ctr electronics com ______________________ 1 31 2022 Cross The Road Electronics Page 1 ____________________________ 1 31 2022 Pigeon 2 0 User s Guide Revision 1 0 Cross The Road Electronics www ctr electronics com ...

Page 2: ...Rotation 11 2 2 Temperature 11 2 3 Gyroscope Sensitivity Error 12 2 4 Avoid Magnetic Ferromagnetic materials 13 2 5 Vibration 14 2 6 Saturated inputs 14 3 Calibration 15 3 1 Temperature Calibration 15 3 2 Gyroscope Bias Calibration 15 3 3 Gyroscope Sensitivity Calibration 15 3 4 Accelerometer Calibration 15 3 5 Compass Calibration 15 4 Boot behavior 16 4 1 Boot behavior Test Results 17 5 Wiring 19...

Page 3: ...do I change the Mount Orientation 24 7 3 What changes do I need to make when upgrading from Pigeon 1 IMU to Pigeon 2 0 24 7 4 What are the requirements of Pigeon 2 0 when booting up 24 7 5 Does the device support CAN FD 24 7 6 Trying to keep robot from tipping over Any suggestions 24 7 7 Closed looping an Arm Any suggestions 24 7 8 When Pigeon IMU boots starting Yaw is not zero 24 8 Mechanical Dra...

Page 4: ...ued customers with the best documentation possible to ensure successful use of your CTRE products To this end we will continue to improve our publications examples and support to better suit your needs If you have any questions or comments regarding this document or any CTRE product please contact support crosstheroadelectronics com To obtain the most recent version of this document please visit w...

Page 5: ...ds With this information Pigeon 2 0 can be used to sense a mobile platform s pose which then can be used for a variety of applications 1 1 Kit Contents Each kit contains a single Pigeon 2 0 IMU IMU is preassembled and includes wire leads for power and CAN bus The CAN bus wire leads are terminated with 3 pin pre installed connectors 0 1 pitch One lead pair has a female connector and the other has a...

Page 6: ...Enclosure protects against debris Wide Input Voltage Range 6V 28V Protection Reverse Input Power Protection Polycarbonate housing prevents debris from entering inside device One wire lead pair for power Two wire lead pairs for CAN Bus 3 pin connector one male one female for daisy chaining devices Robust bootloader and reliable field upgrade no physical button required no stuck states that requires...

Page 7: ...otion which reduces drift rate to DR NO MOTION Note 3 Stresses above listed rating may cause permanent damage to the device Symbol Parameter Condition Min Typ Max Unit Tamb Ambient temperature 40 85 C Isupp Supply Current DC supply 12 0V DC supply 28 0V 40 21 46 23 mA Vdd Supply voltage 6 0 12 0 28 0 V ESD Rating ESD Protection Contact Discharge 30 kV ESD Protection Air Gap Discharge 30 kV Yaw Dri...

Page 8: ...r most likely because field upgrade failed in middle of event Inspect CAN bus wiring and re field upgrade using Phoenix Tuner If device has valid firmware turn device off wait 10 seconds and turn device on to boot strap it Red Yellow LEDs are never off one of the two colors are always illuminated Hardware is damaged Red Blink Check CAN Bus health and connection to the Pigeon 2 0 Yellow Alternate B...

Page 9: ... Mount Orientation 1 6 2 Enclosure Orientated Signals The outputs of the gyroscope accelerometer and magnetometer are not compensated for the selected Mount Orientation These signals are biased calibrated to canonical units Note 1 As a result these signals are referenced to the enclosure s orientation If these enclosure oriented signals are used it is recommended to choose a Mount Orientation that...

Page 10: ... up Axes conventions X points to right Y points to forward Z points to sky Pitch is about X Roll is about Y Yaw is about Z X points forward Y points to the left Z points to the sky Pitch is about Y Roll is about X Yaw is about Z Mount orientation Must be mounted flat and level Z axis pointed up Mount in any orientation Orientation does not need to be purely vertical or horizontal Pitch and Roll ca...

Page 11: ...cumulated gyro Z value is more correct than the Yaw it sufficiently confirms the root cause Procedure 1 First drive the robot to immoveable flat obstacle A wall works best against the robot s flattest surface 2 Zero the yaw and accumulated gyro Z 3 Drive the robot in a zero turn at max speed for 30 seconds 4 Drive the robot in the opposite direction at max speed until it approaches 0 heading 5 Dri...

Page 12: ...measure and trim the sensitivity error correction This can be measured by the following procedure 1 First drive the robot to immoveable flat obstacle A wall works best against the robot s flattest surface 2 Zero the yaw and accumulated gyro Z 3 Drive the robot in a zero turn at max speed for 10 rotations 4 Drive back up against the obstacle and read Yaw It should be 3600 expected drift for the dur...

Page 13: ...E Mag Encoder CANcoder magnets This impact can be root caused by waving a simple mechanical compass in the presence of where the IMU is intended to be placed Look for any major changes in the needle position as the compass is waved near the critical areas of the robot while maintaining consistent orientation between compass and Earth Next place the mechanical compass in the location where the IMU ...

Page 14: ... enough a sensor input may see a saturated value A common example of this is vibration in the airframe of a UAV drone for example and unbiased propeller 2 6 Saturated inputs Pigeon 2 0 will mark a sticky fault if a sensor measurement is saturated This is useful in determining if sensitivity configurations are too high or if the Pigeon physical mount needs dampening Typically a rigid mount to the r...

Page 15: ...surement overshot or produced a magnitude above expected value Similarly sensitivity error is negative if measurement undershot or produced a magnitude below expected value Example below 1 Perform test procedure in Section 2 3 2 IMU reports Yaw travel from 0 deg to 3602 deg 3 However mechanically IMU traveled 3600 deg 4 Therefore measurement overshot by 2 deg 5 Set corrective error amount to 0 2 d...

Page 16: ... 0 can predict the gyroscope bias during boot up This allows it to produce reasonable heading information immediately on boot even when in motion This is a particularly important feature to resolve complications due to IMU is booting up in environment with vibration sources fans compressors user handling IMU is booting up with extremely loud music in near proximity also a vibration source IMU is b...

Page 17: ...s were all power booted during vibration and drift was tracked over time The ongoing vibration prevents all three IMUs from performing no motion calibration 4 1 1 Boot behavior Drift Rates Device Change in Yaw over 30 sec Drift Pigeon 1 0 Note 1 1 8 deg 3 6 deg per min Other 2nd Generation Competitor IMU Note 2 20 deg 40 deg per min Pigeon 2 0 0 10 deg 0 2 deg per min Note 1 Pigeon 1 0 User s Guid...

Page 18: ..._________________ 1 31 2022 4 1 2 Boot behavior Accelerometer Note 1 Source of vibration is in the Y and Z axis therefore X axis measurements are reduced in comparison Legend ax Pigeon 2 Accelerometer X Axis ay Pigeon 2 Accelerometer Y Axis az Pigeon 2 Accelerometer Z Axis X axis 0 5 seconds per gradient Y axis 2 5 mg per gradient ...

Page 19: ...__________________________ 1 31 2022 5 Wiring Pigeon 2 0 comes with wires pre installed on it The leads should be wired following the table below Color Signal Red Vdd Black Ground Yellow Note 1 2 CANH Green Note 1 2 CANL Note 1 The two yellow wires are electrically common Note 2 The two green wires are electrically common ...

Page 20: ...his Yaw is defined as travel about the plane orthogonal to gravity Therefore the Pigeon 2 0 does not require being aligned to gravity for reliable Yaw 6 3 Gimble Lock Given the angle definitions used by Pigeon 2 0 Gimble Lock occurs when the Pitch reaches near 90 degrees At this location the tip of the airplane would be aligned with World Frame Reference Z Axis At this point Roll and Yaw cannot be...

Page 21: ...nclosure X axis is parallel to gravity points to sky or ground If the orientation ensures enclosure X axis is not near parallel to gravity then the default Mount Orientation settings are acceptable This includes common orientations where the Pigeon 2 0 is Z up Z down Y up and Y down Alterative orientations that risk enclosure X axis reaching near parallel to gravity should use a Custom Mounting Or...

Page 22: ... IMU s X Axis or a 90 degree Roll If the Mount Orientation Configuration Values Yaw Pitch Roll are set to 0 deg 0 deg 90 deg Note 1 2 the Pigeon 2 will re orient the Euler Angles and Gravity Vector Quaternion so that Pitch and Roll will report 0 deg Additionally rotation about the top robot axis will be measured as Yaw ideal for ground vehicles Note 1 The Mount Orientation Angles can be specified ...

Page 23: ...ation button Once pressed Pigeon LEDs will rapid blink orange same LED pattern as blink command in Tuner Then tilt the robot Once robot is sufficiently tilt Pigeon will rapid blink green briefly to confirm success The axis the robot was tilted about will become the Roll axis Confirm near zero Pitch and Roll using Self Test Confirm basic Yaw by rotating robot and checking Self Test The calculated c...

Page 24: ...ctrical Specifications 7 5 Does the device support CAN FD Yes Pigeon 2 0 supports CAN FD with a CTRE CANivore 7 6 Trying to keep robot from tipping over Any suggestions Generally robots are tipped due to a combination of a high center of gravity and excessive acceleration by the drivetrain In advanced cases software can be developed to prevent the robot from tipping by monitoring the Gravity Vecto...

Page 25: ...Pigeon 2 0 User s Guide ___ www ctr electronics com ______________________ 1 31 2022 Cross The Road Electronics Page 25 ____________________________ 1 31 2022 8 Mechanical Drawings ...

Page 26: ... Guide ___ www ctr electronics com ______________________ 1 31 2022 Cross The Road Electronics Page 26 ____________________________ 1 31 2022 9 Revision History Revision Date Description 1 0 31 Jan 2022 Initial Release ...