nerdCopter's EmuFlight Tuning Guide for FreeStyle

# nerdCopter's EmuFlight Tuning Guide for FreeStyle * This will get you 80+++% there (Filters & PIDs) * Squeezing the best performance will be up to you to fine-tune * Tune the setup that you intend to fly, use the camera, lipo, props you expect to normally fly. Changing any of these may require re-tuning. ## Setup ESC's first (BLHeli, BlueJay, etc.) * Setup your ESC's however you like, but some good tips are: * Demag-Compensation High (or Medium-to-High if applicable). This will avoid in-flight de-syncs. * Ramp-up power 30% for most mini-quads. (Ryan Harrell said 25%, but i like headroom.) Toothpick and ultralights may need alternative tuning. (*This is totally debatable, keep at default 50% if any question.) * Variable PWM (latest versions) is good. Set Max-PWM to variable. For 5-inch, set Min-PWM to 32 or 48khz. If variable PWM is not available, 48Khz is generally good. For 7" set Min-PWM to 24 or 32khz. Other sizes may need alternative tuning. * Timing as you like, Auto is good enough and will fly the longest but least "performant". 23°-25° is good for 32-bit ESC. Higher values may be more "performant" at cost of flight time. * No AMP limiting (Current) or very high AMP limiting (105+). * No, Sine-Modulation; it apparently has no significant help. ## Pre-Tuning * EmuFlight Defaults are generic and safe for 5 inch quads. It may be over-filtered or under-performant. * EmuFlight Presets are generally good, but also may not be "locked-in" for your quad. * Turn off ADC Filter in EdgeTX, OpenTX, etc. * Radio-link has a direct effect on setpoint and thus affects PIDs. Defaults may work for some RX/TX links, but not all. Consider setting Interpolation, Manual, 21, RPYT if you do not wish to tune RC-Smoothing. ### Step 1 : Motor Protocol * Select a DShot of choice (recommended); This is a digital protocol and does not need calibration. * If selecting MultiShot, this analog protocol *requires* ESC-calibration and is dangerous to the hardware until performed. * Most motors have 14 magnets. If your motors have another count, be sure to set `motor_poles` in the CLI. ### Step 2 : BlackBox Logging * Setup blackbox to log at 1.5Khz or better. * `set debug_mode = gyro_scaled`. * Test-hover checking motor temperatures. If motors are not hot, then continue. If motors are hot, then check your hardware for faults and reduce Roll/Pitch `D`. * Record blackbox without hitting obstacles, or LOS fly in your back yard. An appropriate amount of Roll and Pitch movement are needed, flips and rolls are better, but a backyard LOS can get the basic data to start tuning. ### Step 3 : Filters First * Open logs in EmuFlight Blackbox explorer (https://github.com/emuflight/EmuFlight-Blackbox-Explorer/releases). * View the frequency analyzer for gyro_scaled per each axis. * Set Gyro LPF #1 lower than the primary noise-profile (default is usually good). * Helio®-Specific: If Helio-based FC's, then use IMUF-LPF's not Gyro-LPF. `ptn_order` 2 (PT2) is a good choice. * Set the `dynamic_filter`'s Min and Max to cover the primary noise-profile. Typically 150Hz to 400Hz+ on 5-inch. Lower for larger quads. Higher for smaller quads. * Decide if you prefer to use dynamic_filter enabled or disabled. * If enabled, then in most circumstances, set the first d-Term LPF type to PT2 and disable the second d-Term LPF altogether. * Tune the first D-Term LPF cutoff to below the primary noise profile. Lower values are more filtering at cost of delay (over-filtering), higher values are less filtering at cost of motor-heat (under-filtering). * Note that d-term LPF tuning is really important. Do see the wiki for alternative tuning options: https://github.com/emuflight/EmuFlight/wiki/LowPassFilters#filter-tuning-tips. Choices include 100% static filtering, dynamic_filter with single dLPF (described here) or dynamic_filter (Gyro) AND Dynamic-D-Notch. * "IMU-F" Kalman-based filter: Lower Q is more gyro-filtering, Higher Q is less Filtering. Recommended 9000+. Larger craft, smaller Q. W is how much gyro data is used to calculate the kalman filtering. Smaller feels sharper, larger feels smoother. Smaller W for combatting wind. Smaller craft, smaller W. Larger craft, larger W. * Repeat step 3 as needed. #### Filter considerations * over-filtering will cause poor prop-wash handling. * over-filtering can cause feedback-loop, oscillations, and fly-offs. * under-filtering can cause hot motors. * Larger quads generally need lower LPF cutoffs. * Smaller quads gernarlly need higher LPF cutoffs. * Gyro filter order: kalman, static notch, lpf1, lpf2, dynamic notch, ABG * D-Term filter order: lpf1, lpf2, dynamic notch, ABG ### Step 4 : PIDs * Open logs in PID Tool box (https://github.com/bw1129/PIDtoolbox/releases). * Run Step-Response tool. * Use the step-response graphing to find a good PID balance (P/D ratio). * Typically more Roll/Pitch D is needed than defaults. * Possibly less Roll/Pitch I-term is needed than default. Too high I-terms will always overshoot initial step-response. * Raise Roll/Pitch P/D in balance as needed to combat high winds. * Almost always more Yaw P-term (80+) and more yaw I-Term (90+) is needed than defaults. Typically do not increase yaw D over 5. * Repeat step 4 as needed until relatively "flat-line" step responses or acceptably balanced Roll/Pitch. #### PID considerations * D dampens overshoot/oscillation caused by high P. * Too low D allows P to overshoot, oscillate, and wobble. * Too high D can cause motor heat, oscillation, and possibly fly-aways. * Find a good P/D ratio and they can be increased or decreased while keeping them in balance. * High I-Term can keep a quad from being affected by outside forces. Making it "stick" into position better. * Too high I-Term will be too robotic. * Too high I-Term will pull the P-Term too much and cause an initial hump in the step-response graphs. * 7-inch and larger craft, do not need as much I-Term because a larger craft has stronger inherit authority. * 7-inch and larger craft may not need very high yaw P. * Pitch generally need higher PIDs due to how HD cameras and LiPo batteries are mounted * Whoops Roll/Pitch are usually 1:1 * To tune PIDs from scratch, see MadChiller's baseline PIDs: https://hackmd.io/XwPQyN7OS9CspZZndNz-tg (Basically find the PIDs that move closest to 1.0 in PTB's step-response, then tune D for better P/D ratio, then lastly tune I.) ### Step 5 : Optional * Better performance be achieved be repeating steps 3 and 4 round-robin; However, at some point it becomes unwarranted chasing because changes to either will affect the other. * Fine tuning can encompass some of the following: * i-Decay default of 4 may be too much for 5-inch. Consider dropping to 2 or 3. Larger quads may want a bit higher values. * Larger quads may need smaller than default i-Relax values. * Feathered can be adjusted 0 to 100. Where 0 is calculated "on error" like KISS and 100 is calculated "on measurement" like Betaflight. Closer to 0 may be more responsive but less tolerant to high D's. I prefer `50` for a balance of the two. * EmuBoost boosts P & I error during PID calculations. Higher Boost will increase feel-response, increase as much as desired. Limit should not be overly high. Typically not over 80% of your roll's P value, but tune as desired. * D-Boost is typically not needed. D-Boost limit should remain very small (2% to 5%); otherwise it may induce oscillation same as too much D would. * EmuGravity increases "error" on throttle-change and can help reduce dolphin-effect on throttle-bumping. Increase as needed in increments of 5 or 10. Too much may induce flutter during flight. ### Step 6 : Advanced * TPA changes P, I, & D values base on throttle. TPA tuning can repair oscillation on high throttle; However, the need for TPA can be bypassed with `Thrust Linearization` as well. * Motor output mixer can be set to alternate smoothing types. `Legacy` was present since day 0, and some people prefer the old feel. Default is `2pass` which can be elevated to an even smoother `Thrust Linearization` by enabling `Laziness` and tuning both the high and low rpm compensation. See: https://github.com/emuflight/EmuFlight/wiki/Motor-Mixers-and-Thrust-Linearization * Axis-Lock can make your quad feel more locked in. * Enable expert-mode in the configurator to access per-axis LPF's. * Enable expert-mode in the configurator to access ABG filters. I really like ABG filters in conjunction with Static LPF's (but not necessarily with dynamic_filter). ### Prop-Wash handling * Poor prop-wash handling can be caused by too much filtering. * Poor prop-wash handling can be caused by poor P/D balance. * Prop-wash handling can be affected by too low motor idle speed. ### Final Thoughts * As with all tuning, every quad is different and some settings may or may not be best suited for the application. * Further stick-feel and flight-feel can be achieved with rateDynamics and Dual-Axis-Steering. * DShot1200 and above can result in smoother cooler motors if the ESC's supports it. CPU utilization is NOT significantly increased by EmuFlights implementation of dShot. * Enable expert-mode in the configurator to access GPS OSD elements. * Enable expert-mode in the configurator to access Angle/Horizon PIDs * Everything is in the wiki: https://github.com/emuflight/EmuFlight/wiki ### Notable resources * Oscar Liang How to Tune via BBL: https://oscarliang.com/pid-filter-tuning-blackbox/#Tuning-goals * PID Animiation: https://en.wikipedia.org/wiki/File:PID_Compensation_Animated.gif * PIDs simplified: https://www.youtube.com/watch?v=6OH-wOsVVjg * P/D https://www.youtube.com/watch?v=J-cGppT_qKQ * PID Step-Response: https://www.youtube.com/watch?v=NPS3aJqoFko * P/I https://www.youtube.com/watch?v=OAki11gcsSI * PID tuning by feel: https://www.youtube.com/watch?v=ehyXLsvaEhw * Tune with plasmaTree: https://www.getfpv.com/learn/fpv-in-depth-and-technical/tuning-your-fpv-drone-with-plasmatree-pid-analyzer/ * RC Interpolation tuning: https://www.youtube.com/watch?v=QNBhpkSNRB0 * JB/Harrell full BLHeli series: https://www.youtube.com/playlist?list=PLwoDb7WF6c8kXOyPdBog1wtRcxnXMasUb * JB/Harrell desync specific: https://www.youtube.com/watch?v=oKcyXR7Yx64 (@21:17) * Kabab micro rampup: https://www.youtube.com/watch?v=obObn1oGWmU <-- read Mr.ShutterBug's comment as well! * JB's variable PWM https://www.youtube.com/watch?v=xuQeJA4EGr8 * JB's 16bit esc: https://youtu.be/yEDhnBUFQNI * Bluejay config migration: https://github.com/mathiasvr/bluejay/wiki/Migrating-from-BLHeli_S * JB's 32bit AM32 vid: https://youtu.be/yOeVj6P9PSU * AM32: https://github.com/AlkaMotors/AM32-MultiRotor-ESC-firmware/releases * https://esc-configurator.com/ (use in Chrome, not Firefox)