Sensors/IMU - Revision history

Podhrmic at 21:23, 5 March 2017

2017-03-05T21:23:53Z

← Older revision		Revision as of 15:23, 5 March 2017
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	The code is available, use it as an INS subsystem (ins_vectornav). Comes with recommended configuration target (setup_vectornav) so it can be easily configured. Another option is to use the Windows configuration tool from Vectornav.		The code is available, use it as an INS subsystem (ins_vectornav). Comes with recommended configuration target (setup_vectornav) so it can be easily configured. Another option is to use the Windows configuration tool from Vectornav.

			Recommended Vectornav configuration is recorded in this [https://docs.google.com/spreadsheets/d/1JJIN4E16M2ii-TDnkjxinNSCmxCxwGGYOY_cep56z00/edit?usp=sharing table]. In the future there could be a configuration module as a part of paparazzi, for the time being an external configuration tool is required (it is provided in sw/tools/vectornav_configurator).

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IHaveADrone: spelling

2016-06-08T13:50:51Z

spelling

← Older revision		Revision as of 07:50, 8 June 2016
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	== 3rd Party IMU ==		== 3rd Party IMU ==

	'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z ~~cartesian~~ directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.		'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z Cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

	IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.		IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.
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	[http://www.xsens.com/en/general/mti-g Official website MTi-G]		[http://www.xsens.com/en/general/mti-g Official website MTi-G]

	In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in ~~paparazi~~.		In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazzi.

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	A = B + C + D		A = B + C + D

	You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you ~~accerate~~ to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on ~~youtube~~ look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.		You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accelerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on Youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

	Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.		Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

Podhrmic at 18:25, 27 August 2015

2015-08-27T18:25:58Z

← Older revision		Revision as of 12:25, 27 August 2015
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	The code is available, use it as an INS subsystem (ins_vectornav). Comes with recommended configuration target (setup_vectornav) so it can be easily configured. Another option is to use the Windows configuration tool from Vectornav.		The code is available, use it as an INS subsystem (ins_vectornav). Comes with recommended configuration target (setup_vectornav) so it can be easily configured. Another option is to use the Windows configuration tool from Vectornav.

	=== MicroStrain 3DM-GX2 ===		<br style="clear:both">

			=== MicroStrain 3DM-GX2/3 ===
	[[Image:3DM-GX2.jpg\|thumb\|left\|MicroStrain 3DM-GX2]]		[[Image:3DM-GX2.jpg\|thumb\|left\|MicroStrain 3DM-GX2]]

	[http://www.microstrain.com/3dm-gx2.aspx Official website]		[http://www.microstrain.com/3dm-gx2.aspx Official website GX2]
			[http://www.microstrain.com/inertial/3DM-GX3-25-OEM Official website GX3]

	~~More info soon~~.		GX3 AHRS (ahrs_gx3.xml) available for both fixedwing and rotorcraft. Can be used for GX2 too, since the commands and packets are identical (GX2 has slower update rate).

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Podhrmic at 18:23, 27 August 2015

2015-08-27T18:23:38Z

← Older revision		Revision as of 12:23, 27 August 2015
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			=== Vectornav VN-200 ===
			[[File:Vn-200-rugged.png\|thumb\|left\|VN-200 Rugged version]]
			[[File:Vn-200-smd.gif\|thumb\|left\|VN-200 SMD version]]

			[http://www.vectornav.com/products/vn200-rugged Official website Rugged version]
			[http://www.vectornav.com/products/vn200-smd Official website SMD version]

			Vectornav VN-200 is a relatively new (2015) INS solution. In our tests it outperforms GX2/3 and has similar performance as MTI-G (see white paper ''A Comparison of Flight Data from 5 Small Low-cost IMUs'' from Nathan V. Hoffer, Calvin Coopmans, Austin M. Jensen, AggieAir at the Utah Water Research Laboratory) at roughly half price.

			The code is available, use it as an INS subsystem (ins_vectornav). Comes with recommended configuration target (setup_vectornav) so it can be easily configured. Another option is to use the Windows configuration tool from Vectornav.

	=== MicroStrain 3DM-GX2 ===		=== MicroStrain 3DM-GX2 ===

NeoFromMatrix: /* Drotek 10DOF (MPU6050-HMC5883-MS5611) */

2014-08-21T17:25:17Z

Drotek 10DOF (MPU6050-HMC5883-MS5611)

← Older revision		Revision as of 11:25, 21 August 2014
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	It is a low cost and precise solution for normal aircraft with a excellent baro sensor.		It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

	~~Driver: drotek_10dof_v2~~		By default the axes orientation should be as printed on the pcb, meaning z-axis pointing down if ICs are facing down. The orientation can be switched so that the IMU can be mounted ICs facing up by defining IMU_DROTEK_2_ORIENTATION_IC_UP.#
	By default the axes orientation should be as printed on the pcb, meaning z-axis pointing down if ICs are facing down. The orientation can be switched so that the IMU can be mounted ICs facing up by defining IMU_DROTEK_2_ORIENTATION_IC_UP.
			Maybe setting a different I2C address is required.

			{{Box Code\|conf/airframes/myplane.xml\|
			<source lang="xml">
	<subsytem name="imu" type="drotek_10dof_v2">		<subsytem name="imu" type="drotek_10dof_v2">
			...
	<configure name="DROTEK_2_I2C_DEV" value="i2c0"/>		<configure name="DROTEK_2_I2C_DEV" value="i2c0"/>
			<!--define name="DROTEK_2_MPU_I2C_ADDR" value="MPU60X0_ADDR" /-->
			<define name="IMU_DROTEK_2_ORIENTATION_IC_UP" value="1" />
	</subsystem>		</subsystem>
			</source>
			}}

			To read the baro use the separate [[Module/Meas_Spec_MS5611_I2C\| baro_ms5611 module]].

	~~To read the baro use the separate baro_ms5611 sensor driver~~.		Similar chinese breakout boards (different pinout/pcb size) can be found on ebay starting at 12€.

	~~Similar chinese breakout boards can be found on ebay starting at 12€.~~

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NeoFromMatrix: /* 3rd Party IMU */ drotek, added note about availability on ebay china

2014-07-16T11:26:11Z

3rd Party IMU: drotek, added note about availability on ebay china

← Older revision		Revision as of 05:26, 16 July 2014
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	=== PPZUAV IMU 9DOF ===		=== PPZUAV IMU 9DOF ===

	<gallery>		<gallery>
	Image:Ppz9dofimu.jpg\|9DOM IMU		Image:Ppz9dofimu.jpg\|9DOM IMU
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	=== SparkFun Razor 6DOF IMU ===		=== SparkFun Razor 6DOF IMU ===

			'''This product has been discontinued by the manufacturer ! '''

	[[Image:RazzorIMU.jpg\|thumb\|left\|Razor IMU (top) with the tiny13 autopilot]]		[[Image:RazzorIMU.jpg\|thumb\|left\|Razor IMU (top) with the tiny13 autopilot]]
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	Tiny, very low cost 12 € , 5V and 3.3V input, I2C interface.		Tiny, very low cost 12 € , 5V and 3.3V input, I2C interface.

	~~This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarim, YAPA and flown with YAPA.~~		Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.
	Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

			Similar chinese breakout boards can be found on ebay starting at 2€.

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	=== Drotek 10DOF (MPU6050-~~hmc5883~~-~~ms5611~~) ===		=== Drotek 10DOF (MPU6050-HMC5883-MS5611) ===


	[[Image:drotek3.jpg\|thumb\|left\|component side]]		[[Image:drotek3.jpg\|thumb\|left\|component side]]
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	[http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html drotek.fr shop]		[http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html drotek.fr shop]

	Tiny, low cost 23€, 5V and 3.3V input, I2C interface.		Tiny, low cost 23€, 5V and 3.3V input (onboard voltage regulator), I2C interface.
	It is a low cost and precise solution for normal aircraft with a excellent baro sensor.		It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

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	To read the baro use the separate baro_ms5611 sensor driver.		To read the baro use the separate baro_ms5611 sensor driver.

			Similar chinese breakout boards can be found on ebay starting at 12€.


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	=== SparkFun SEN-10121 ===		=== SparkFun SEN-10121 ===

	[[Image:SEN-10121.jpg\|thumb\|left\|SEN-10121]]		[[Image:SEN-10121.jpg\|thumb\|left\|SEN-10121]]

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	=== Pololu MinIMU-9 ===		=== Pololu MinIMU-9 ===

			'''This product has been discontinued by the manufacturer !'''

	[[Image:MinIMU9.jpg\|thumb\|left\|MinIMU-9]]		[[Image:MinIMU9.jpg\|thumb\|left\|MinIMU-9]]
	~~This product has been discontinued by the manufacturer !~~

	IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303		IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303
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	=== Cloudcap Crista IMU ===		=== Cloudcap Crista IMU ===

	[[Image:crista_sensorhead.jpg\|thumb\|left\|Christa IMU]]		[[Image:crista_sensorhead.jpg\|thumb\|left\|Christa IMU]]

NeoFromMatrix: /* Drotek 10DOF (MPU6050-hmc5883-ms5611) */

2014-01-05T23:13:26Z

Drotek 10DOF (MPU6050-hmc5883-ms5611)

← Older revision		Revision as of 17:13, 5 January 2014
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	IMU Drotek MPU6050 - 10 Degrees of Freedom		IMU Drotek MPU6050 - 10 Degrees of Freedom

	http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html		[http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html drotek.fr shop]

	Tiny, low cost ~~< 30 € ( < 25 € on their Ebay site)~~, 5V and 3.3V input, I2C interface.		Tiny, low cost 23€, 5V and 3.3V input, I2C interface.
	It is a low cost and precise solution for normal aircraft with a excellent baro sensor.		It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

NeoFromMatrix: /* Drotek 6DOF (MPU6050) */

2014-01-05T23:11:27Z

Drotek 6DOF (MPU6050)

← Older revision		Revision as of 17:11, 5 January 2014
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	=== Drotek 6DOF (MPU6050) ===		=== Drotek 6DOF (MPU6050) ===


	[[Image:drotek1.jpg\|thumb\|left\|component side]]		[[Image:drotek1.jpg\|thumb\|left\|component side]]
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	IMU Drotek MPU6050 6 Degrees of Freedom Invensens MPU6050		IMU Drotek MPU6050 6 Degrees of Freedom Invensens MPU6050

	http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html		[http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html drotek.fr shop]

	Tiny, very low cost < 12 € , 5V and 3.3V input, I2C interface.		Tiny, very low cost 12 € , 5V and 3.3V input, I2C interface.

	This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarim, YAPA and flown with YAPA.		This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarim, YAPA and flown with YAPA.

NeoFromMatrix at 21:28, 13 October 2013

2013-10-13T21:28:52Z

← Older revision		Revision as of 15:28, 13 October 2013
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	=== Drotek MPU6050 ===		=== Drotek 6DOF (MPU6050) ===


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	[[Image:drotek2.jpg\|thumb\|left\|solder side]]		[[Image:drotek2.jpg\|thumb\|left\|solder side]]

	IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050		IMU Drotek MPU6050 6 Degrees of Freedom Invensens MPU6050

	http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html		http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html
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	=== Drotek MPU6050-hmc5883-ms5611 ===		=== Drotek 10DOF (MPU6050-hmc5883-ms5611) ===

Flixr: Drotek MPU6050-hmc5883-ms5611 works for rotorcraft as well...

2013-10-11T10:53:23Z

Drotek MPU6050-hmc5883-ms5611 works for rotorcraft as well...

← Older revision		Revision as of 04:53, 11 October 2013
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	http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html		http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html

	~~For ap and fixedwing only !~~

	Tiny, low cost < 30 € ( < 25 € on their Ebay site), 5V and 3.3V input, I2C interface.		Tiny, low cost < 30 € ( < 25 € on their Ebay site), 5V and 3.3V input, I2C interface.