Re: [Paparazzi-devel] Problems with rotorcraft

[Oswald Berthold]

Hi Inaki,

don't know if you have seen it, this pid tuning cookbook is nice and helpful.

http://lists.paparazziuav.org/Copter-tuning-setup-cookbook-step-by-step-td14386.html

if you are flying in ATT mode, you don't need to set parameters for the
RATE mode.

for my particular setup, my current best candidate param set for
ATTITUDE_STABILIZATION is like

    <define name="PHI_PGAIN" value="500"/>
    <define name="PHI_DGAIN" value="300"/>
    <define name="PHI_IGAIN" value="100"/>

    <define name="PHI_DDGAIN" value="250"/>

which deviates significantly from example parameterizations, especially
P. the forward gain just makes response snappier but doesn't affect so
much the dynamic stabilization. if i strongly vary these parameters,
e.g. setting PGAIN of 1000, i just observe oscillations but the aircraft
is still basically maneuverable.

from my recent experiences, if the aircraft really misbehaves, there's
always something fundamentally wrong (wrong ESCs, broken MAG,
MAG/current interaction, vibrations, ...), not just detuned parameters.

bst, oswald


I. Sánchez Ciarrusta writes:

> Hi:
>
>  
>
> I am trying to fly my quadcopter in manual mode (RC or ATT).
>
>  
>
> As is very unstable, it is almost impossible to take off from the ground. So 
> to have more room for maneuver, I fastened with ropes to try to take off to a 
> certain height from the ground. 
>
> Following your advice I'm trying to modify the gains until it becomes stable. 
> However, I need your help because the nomenclature of the terms is not easy 
> to understand. 
>
> I do not know exactly what criteria to follow. I have thought about starting 
> setting zero all the "i"s and "d"s, with low "p"s  (changing from the GCS the 
> values of the ​​tabs "Att Loop" and "Rate Loop",  because I guess "Horiz 
> Loop" and "Vert Loop" have only influence in autonomous modes ).
>
>  
>
> My values are:
>
>  
>
> Rate Loop:
>
> pgain p400
>
> pgain q 400
>
> pgain r 350
>
>  
>
> igain p 75
>
> igain q 75
>
> igain r  50
>
>  
>
> ddgain p 300
>
> ddgain q 300
>
> ddgain r 300
>
>  
>
>  
>
> Att Loop
>
>  
>
> pgain phi 1000
>
> dgain p 400
>
> igain phi 200
>
> ddgain p 300
>
>  
>
> pgain theta 1000
>
> dgain q 400
>
> igain theta 200
>
> ddgain q 300
>
>  
>
> (and the same for yaw)
>
>  
>
>  
>
> I have another question: I usually fly comercial quads, very stable ones. 
> Comercial quad copters (with NO autopiltot) have some kind of help for the 
> stability? Why the one I am using for paparazzi is so unstable (dji f450); i 
> have to change smth in the code?
>
>  
>
> Thank you very much in advance!!!
>
>  
>
> Inaki
>
>  
>
>  
>
>  
>
>
>  
>
>  
>
>
>
> From: address@hidden
> To: address@hidden
> Date: Wed, 9 Jul 2014 09:50:12 +0000
> Subject: Re: [Paparazzi-devel] Problems with rotorcraft
>
>
>
>
> Hi Alonso,
> thanks for your answer.
>  
> I will try that.
>  
> What is the best way for testing if the autopilot acts to control the 
> attitude? Maybe start with AP_MODE:ATTITDE_DIRECT and then pass to "HOVER" or 
> CF mode?
> Is there a standard procedure?
>  
> Perhaps another problem is a bad vibration isolation of the board?
>  
> Thanks again! 
>
>  
>
>
>
> Date: Tue, 8 Jul 2014 22:56:44 -0600
> From: address@hidden
> To: address@hidden
> Subject: Re: [Paparazzi-devel] Problems with rotorcraft
>
>
> maybe you should try the mode  AP_MODE_ATTITUDE_DIRECT, in this mode it does 
> not matter if the barometer works. It is ok to use one battery as long as you 
> are giving the Lisa/M 5V .  You will not get good performance without a 
> barometer in automatic modes. If you have a Aspirin 2.2 then it does have a 
> barometer. Try adding this  <configure name="LISA_M_BARO" 
> value="BARO_MS5611_SPI"/> after <target name="ap" board="lisa_m_2.0">  .  
>
>
>
> On Tue, Jul 8, 2014 at 3:29 AM, I. Sánchez Ciarrusta <address@hidden> wrote:
>
>
>
>
> Hi all.
>  
> I have recently tried to fly a quad (in + configuration) with paparazzi, and 
> it was impossible to fly it.
> It was really difficult to control, absolutelly unstable.
> In addition, sometimes the PFD got “frozen” (and other times responded with 
> delay), with  no apparent reason.
> We tried the hover mode, to observe if the autopilot actuated in every 
> control, but nothing happened.
>  
> We are using Paparazzi v5.1_devel, LisaM/v2 board with NO barometer, aspirin 
> 2.2 IMU, and ublox LEA-5 GPS. 
> The accelerometers and magnetometers are well calibrated.
>   
> Any advice is really appreciated.
>  
> Maybe is a problem because of not having barometer? Maybe the autopilot and 
> the motors have to be alimented with separate batteries?  I saw some reported 
> problems in the mailing list, but I don´t know exactly how related are with 
> my problem.
>  
> Thanks in advance.
>  
> Here is the airframe code we used:
>  
> <!DOCTYPE airframe SYSTEM "../airframe.dtd">
>  
>  
>  
> <airframe name="Quadrotor LisaM_2.0 pwm">
>  
>   <firmware name="rotorcraft">
>     <target name="ap" board="lisa_m_2.0">
>       <define name="NO_RC_THRUST_LIMIT"/>
>     
>       <configure name="AHRS_PROPAGATE_FREQUENCY" value="500"/>
>     </target>
>  
>     <target name="nps" board="pc">
>       <subsystem name="fdm" type="jsbsim"/>
>       <subsystem name="radio_control" type="ppm"/>   
>     </target>
>  
>     <subsystem name="motor_mixing"/>
>     <subsystem name="actuators"     type="pwm">
>       <define name="SERVO_HZ" value="400"/>
>       
>     </subsystem>
>  
>      <subsystem name="radio_control" type="ppm">        
>         <configure name="RADIO_CONTROL_PPM_PIN" value="SERVO6"/> 
>     </subsystem>
>  
>      <subsystem name="telemetry"     type="transparent">   
>                 <configure name="MODEM_BAUD"    value="B57600"/>
>                 <configure name="MODEM_PORT"    value="UART2"/>
>     </subsystem>
>  
>     <subsystem name="imu"           type="aspirin_v2.2"/> 
>  
>     <subsystem name="gps"           type="ublox">            
>                 <configure name="GPS_PORT"    value="UART3"/>     
>     </subsystem>
>     <subsystem name="stabilization" type="int_quat"/>
>     <subsystem name="ahrs"          type="int_cmpl_quat">
>       <define name="AHRS_GRAVITY_HEURISTIC_FACTOR" value="30"/>
>     </subsystem>
>     <subsystem name="ins"/>  
>  
>     <!--define name="KILL_ON_GROUND_DETECT" value="TRUE"/-->
>     <define name="TELEMETRY_MODE_FBW" value="1" />
>   </firmware>
>  
>  
>   <modules main_freq="512">
>  
>   <load name="gps_ubx_ucenter.xml">            
>                 <define name="GPS_UBX_NAV5_DYNAMICS"  
> value="NAV5_DYN_PEDESTRIAN"/>
>                 
>   </load>
>   </modules>
>   <servos driver="Pwm">
>     <servo name="FRONT"   no="0" min="1000" neutral="1100" max="1900"/>
>     <servo name="BACK"    no="1" min="1000" neutral="1100" max="1900"/>
>     <servo name="RIGHT"   no="2" min="1000" neutral="1100" max="1900"/>
>     <servo name="LEFT"    no="3" min="1000" neutral="1100" max="1900"/>
>   </servos>
>  
>   <commands>
>     <axis name="ROLL"   failsafe_value="0"/>
>     <axis name="PITCH"  failsafe_value="0"/>
>     <axis name="YAW"    failsafe_value="0"/>
>     <axis name="THRUST" failsafe_value="0"/>
>   </commands>
>  
>   <section name="MIXING" prefix="MOTOR_MIXING_">
>     <define name="TRIM_ROLL" value="0"/>
>     <define name="TRIM_PITCH" value="0"/>
>     <define name="TRIM_YAW" value="0"/>
>     <define name="NB_MOTOR" value="4"/>
>     <define name="SCALE" value="256"/>
>     <!-- front/back turning CW, right/left CCW -->
>     <define name="ROLL_COEF"   value="{    0,    0, -256,  256 }"/>
>     <define name="PITCH_COEF"  value="{  256, -256,    0,    0 }"/>
>     <define name="YAW_COEF"    value="{ -256, -256,  256,  256 }"/>
>     <define name="THRUST_COEF" value="{  256,  256,  256,  256 }"/>
>   </section>
>  
>   <command_laws>
>     <call fun="motor_mixing_run(autopilot_motors_on,FALSE,values)"/>
>     <set servo="FRONT"  value="motor_mixing.commands[SERVO_FRONT]"/>
>     <set servo="BACK"   value="motor_mixing.commands[SERVO_BACK]"/>
>     <set servo="RIGHT"  value="motor_mixing.commands[SERVO_RIGHT]"/>
>     <set servo="LEFT"   value="motor_mixing.commands[SERVO_LEFT]"/>
>   </command_laws>
> <!-- inaki he puesto mis valores-->
>   <section name="IMU" prefix="IMU_">
>    <define name="ACCEL_X_NEUTRAL" value="24"/>
>   <define name="ACCEL_Y_NEUTRAL" value="8"/>
>   <define name="ACCEL_Z_NEUTRAL" value="264"/>
>   <define name="ACCEL_X_SENS" value="4.93314498567" integer="16"/>
>   <define name="ACCEL_Y_SENS" value="4.86671471234" integer="16"/>
>   <define name="ACCEL_Z_SENS" value="4.86346803582" integer="16"/>
>  
>     <!-- REEMPLAZADO POR MI CALIBRACION INAKI -->
>     <define name="MAG_X_NEUTRAL" value="8"/>
>     <define name="MAG_Y_NEUTRAL" value="-12"/>
>     <define name="MAG_Z_NEUTRAL" value="35"/>
>     <define name="MAG_X_SENS" value="3.53511175627" integer="16"/>
>     <define name="MAG_Y_SENS" value="3.49864611794" integer="16"/>
>     <define name="MAG_Z_SENS" value="3.96410626337" integer="16"/>
>  
>     <define name="BODY_TO_IMU_PHI"   value="0." unit="deg"/>
>     <define name="BODY_TO_IMU_THETA" value="0." unit="deg"/>
>     <define name="BODY_TO_IMU_PSI"   value="0." unit="deg"/>
>   </section>
>  
>   <section name="AHRS" prefix="AHRS_">
>     <define name="H_X" value="0.3770441"/>
>     <define name="H_Y" value="0.0193986"/>
>     <define name="H_Z" value="0.9259921"/>
>   </section>
>  
>   <section name="INS" prefix="INS_">
>   </section>
>  
>   <section name="STABILIZATION_RATE" prefix="STABILIZATION_RATE_">
>     <!-- setpoints -->
>     <define name="SP_MAX_P" value="10000"/>
>     <define name="SP_MAX_Q" value="10000"/>
>     <define name="SP_MAX_R" value="10000"/>
>     <define name="DEADBAND_P" value="20"/>
>     <define name="DEADBAND_Q" value="20"/>
>     <define name="DEADBAND_R" value="200"/>
>     <define name="REF_TAU" value="4"/>
>  
>     <!-- feedback -->
>     <define name="GAIN_P" value="400"/>
>     <define name="GAIN_Q" value="400"/>
>     <define name="GAIN_R" value="350"/>
>  
>     <define name="IGAIN_P" value="75"/>
>     <define name="IGAIN_Q" value="75"/>
>     <define name="IGAIN_R" value="50"/>
>  
>     <!-- feedforward -->
>     <define name="DDGAIN_P" value="300"/>
>     <define name="DDGAIN_Q" value="300"/>
>     <define name="DDGAIN_R" value="300"/>
>   </section>
>  
>  
>   <section name="STABILIZATION_ATTITUDE" prefix="STABILIZATION_ATTITUDE_">
>     <!-- setpoints -->
>     <define name="SP_MAX_PHI"     value="45." unit="deg"/>
>     <define name="SP_MAX_THETA"   value="45." unit="deg"/>
>     <define name="SP_MAX_R"       value="90." unit="deg/s"/>
>     <define name="DEADBAND_A"     value="0"/>
>     <define name="DEADBAND_E"     value="0"/>
>     <define name="DEADBAND_R"     value="250"/>
>  
>     <!-- reference -->
>     <define name="REF_OMEGA_P"  value="400" unit="deg/s"/>   
>     <define name="REF_ZETA_P"   value="0.85"/>
>     <define name="REF_MAX_P"    value="400." unit="deg/s"/>
>     <define name="REF_MAX_PDOT" value="RadOfDeg(8000.)"/>
>  
>     <define name="REF_OMEGA_Q"  value="400" unit="deg/s"/>
>     <define name="REF_ZETA_Q"   value="0.85"/>
>     <define name="REF_MAX_Q"    value="400." unit="deg/s"/>
>     <define name="REF_MAX_QDOT" value="RadOfDeg(8000.)"/>
>  
>     <define name="REF_OMEGA_R"  value="250" unit="deg/s"/>
>     <define name="REF_ZETA_R"   value="0.85"/>
>     <define name="REF_MAX_R"    value="180." unit="deg/s"/>
>     <define name="REF_MAX_RDOT" value="RadOfDeg(1800.)"/>
>  
>     <!-- feedback -->
>     <define name="PHI_PGAIN"  value="1000"/>
>     <define name="PHI_DGAIN"  value="400"/>
>     <define name="PHI_IGAIN"  value="200"/>
>  
>     <define name="THETA_PGAIN"  value="1000"/>
>     <define name="THETA_DGAIN"  value="400"/>
>     <define name="THETA_IGAIN"  value="200"/>
>  
>     <define name="PSI_PGAIN"  value="500"/>
>     <define name="PSI_DGAIN"  value="300"/>
>     <define name="PSI_IGAIN"  value="10"/>
>  
>     <!-- feedforward -->
>     <define name="PHI_DDGAIN"   value="300"/>
>     <define name="THETA_DDGAIN" value="300"/>
>     <define name="PSI_DDGAIN"   value="300"/>
>   </section>
>  
>   <section name="GUIDANCE_V" prefix="GUIDANCE_V_">
>     <define name="MIN_ERR_Z"   value="POS_BFP_OF_REAL(-10.)"/>
>     <define name="MAX_ERR_Z"   value="POS_BFP_OF_REAL( 10.)"/>
>     <define name="MIN_ERR_ZD"  value="SPEED_BFP_OF_REAL(-10.)"/>
>     <define name="MAX_ERR_ZD"  value="SPEED_BFP_OF_REAL( 10.)"/>
>     <define name="MAX_SUM_ERR" value="2000000"/>
>     <define name="HOVER_KP"    value="150"/>
>     <define name="HOVER_KD"    value="80"/>
>     <define name="HOVER_KI"    value="20"/>
>     <define name="NOMINAL_HOVER_THROTTLE" value="0.6"/> 
>     <define name="ADAPT_THROTTLE_ENABLED" value="TRUE"/>
>   </section>
>  
>   <section name="GUIDANCE_H" prefix="GUIDANCE_H_">
>     <define name="MAX_BANK" value="20" unit="deg"/>
>     <define name="USE_SPEED_REF" value="TRUE"/>
>     <define name="PGAIN" value="50"/>
>     <define name="DGAIN" value="100"/>
>     <define name="AGAIN" value="100"/>
>     <define name="IGAIN" value="20"/>
>   </section>
>  
>   <section name="SIMULATOR" prefix="NPS_">
>     <define name="ACTUATOR_NAMES"  value="{&quot;front_motor&quot;, 
> &quot;back_motor&quot;, &quot;right_motor&quot;, &quot;left_motor&quot;}"/>
>     <define name="JSBSIM_INIT" value="&quot;reset00&quot;"/>
>     <define name="JSBSIM_MODEL" value="&quot;simple_quad&quot;"/>
>     <define name="SENSORS_PARAMS" 
> value="&quot;nps_sensors_params_default.h&quot;"/>
>     <!-- mode switch on joystick channel 5 (axis numbering starting at zero) 
> -->
>     <define name="JS_AXIS_MODE" value="4"/>
>   </section>
>  
>   <section name="AUTOPILOT">
>     
>       <define name="MODE_MANUAL" value="AP_MODE_KILL"/>
>       <define name="MODE_AUTO2"  value="AP_MODE_NAV"/>
>       <define name="MODE_AUTO1"  value="AP_MODE_RC_DIRECT"/>
>  
>   </section>
>  
>   <section name="BAT">
>     <define name="CATASTROPHIC_BAT_LEVEL" value="9.3" unit="V"/>
>     <define name="CRITIC_BAT_LEVEL" value="9.6" unit="V"/>
>     <define name="LOW_BAT_LEVEL" value="10.1" unit="V"/>
>     <define name="MAX_BAT_LEVEL" value="12.4" unit="V"/>
>     <define name="MILLIAMP_AT_FULL_THROTTLE" value="30000"/>
>   </section>
>  
> </airframe>
>  
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