/** ****************************************************************************** * * @file vtolpathfollower.c * @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012. * @brief This module compared @ref PositionActual to @ref PathDesired * and sets @ref Stabilization. It only does this when the FlightMode field * of @ref FlightStatus is PathPlanner or RTH. * * @see The GNU Public License (GPL) Version 3 * *****************************************************************************/ /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /** * Input object: FlightStatus * Input object: PathDesired * Input object: PositionActual * Output object: StabilizationDesired * * This module will periodically update the value of the @ref StabilizationDesired object based on * @ref PathDesired and @PositionActual when the Flight Mode selected in @FlightStatus is supported * by this module. Otherwise another module (e.g. @ref ManualControlCommand) is expected to be * writing to @ref StabilizationDesired. * * The module executes in its own thread in this example. * * Modules have no API, all communication to other modules is done through UAVObjects. * However modules may use the API exposed by shared libraries. * See the OpenPilot wiki for more details. * http://www.openpilot.org/OpenPilot_Application_Architecture * */ #include "openpilot.h" #include "paths.h" #include "vtolpathfollower.h" #include "accels.h" #include "attitudeactual.h" #include "hwsettings.h" #include "pathdesired.h" // object that will be updated by the module #include "positionactual.h" #include "manualcontrol.h" #include "flightstatus.h" #include "gpsvelocity.h" #include "gpsposition.h" #include "vtolpathfollowersettings.h" #include "nedaccel.h" #include "nedposition.h" #include "stabilizationdesired.h" #include "stabilizationsettings.h" #include "systemsettings.h" #include "velocitydesired.h" #include "velocityactual.h" #include "CoordinateConversions.h" // Private constants #define MAX_QUEUE_SIZE 4 #define STACK_SIZE_BYTES 1548 #define TASK_PRIORITY (tskIDLE_PRIORITY+2) #define F_PI 3.14159265358979323846f // Private types // Private variables static xTaskHandle pathfollowerTaskHandle; static PathDesiredData pathDesired; static VtolPathFollowerSettingsData guidanceSettings; // Private functions static void vtolPathFollowerTask(void *parameters); static void SettingsUpdatedCb(UAVObjEvent * ev); static void updateNedAccel(); static void updatePathVelocity(); static void updateEndpointVelocity(); static void updateVtolDesiredAttitude(); static float bound(float val, float min, float max); static bool vtolpathfollower_enabled; /** * Initialise the module, called on startup * \returns 0 on success or -1 if initialisation failed */ int32_t VtolPathFollowerStart() { if (vtolpathfollower_enabled) { // Start main task xTaskCreate(vtolPathFollowerTask, (signed char *)"VtolPathFollower", STACK_SIZE_BYTES/4, NULL, TASK_PRIORITY, &pathfollowerTaskHandle); TaskMonitorAdd(TASKINFO_RUNNING_PATHFOLLOWER, pathfollowerTaskHandle); } return 0; } /** * Initialise the module, called on startup * \returns 0 on success or -1 if initialisation failed */ int32_t VtolPathFollowerInitialize() { uint8_t optionalModules[HWSETTINGS_OPTIONALMODULES_NUMELEM]; HwSettingsOptionalModulesGet(optionalModules); if (optionalModules[HWSETTINGS_OPTIONALMODULES_VTOLPATHFOLLOWER] == HWSETTINGS_OPTIONALMODULES_ENABLED) { VtolPathFollowerSettingsInitialize(); NedAccelInitialize(); PathDesiredInitialize(); VelocityDesiredInitialize(); vtolpathfollower_enabled = true; } else { vtolpathfollower_enabled = false; } return 0; } MODULE_INITCALL(VtolPathFollowerInitialize, VtolPathFollowerStart) static float northVelIntegral = 0; static float eastVelIntegral = 0; static float downVelIntegral = 0; static float northPosIntegral = 0; static float eastPosIntegral = 0; static float downPosIntegral = 0; static float throttleOffset = 0; /** * Module thread, should not return. */ static void vtolPathFollowerTask(void *parameters) { SystemSettingsData systemSettings; FlightStatusData flightStatus; portTickType lastUpdateTime; VtolPathFollowerSettingsConnectCallback(SettingsUpdatedCb); PathDesiredConnectCallback(SettingsUpdatedCb); VtolPathFollowerSettingsGet(&guidanceSettings); PathDesiredGet(&pathDesired); // Main task loop lastUpdateTime = xTaskGetTickCount(); while (1) { // Conditions when this runs: // 1. Must have VTOL type airframe // 2. Flight mode is PositionHold and PathDesired.Mode is Endpoint OR // FlightMode is PathPlanner and PathDesired.Mode is Endpoint or Path SystemSettingsGet(&systemSettings); if ( (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_VTOL) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_QUADP) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_QUADP) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_QUADX) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXA) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXAX) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXACOAX) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTO) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTOV) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTOCOAXP) && (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_TRI) ) { AlarmsSet(SYSTEMALARMS_ALARM_GUIDANCE,SYSTEMALARMS_ALARM_WARNING); vTaskDelay(1000); continue; } // Continue collecting data if not enough time vTaskDelayUntil(&lastUpdateTime, guidanceSettings.UpdatePeriod / portTICK_RATE_MS); // Convert the accels into the NED frame updateNedAccel(); FlightStatusGet(&flightStatus); // Check the combinations of flightmode and pathdesired mode switch(flightStatus.FlightMode) { case FLIGHTSTATUS_FLIGHTMODE_RTH: if (pathDesired.Mode == PATHDESIRED_MODE_ENDPOINT) { updateEndpointVelocity(); updateVtolDesiredAttitude(); } else { AlarmsSet(SYSTEMALARMS_ALARM_GUIDANCE,SYSTEMALARMS_ALARM_ERROR); } break; case FLIGHTSTATUS_FLIGHTMODE_POSITIONHOLD: if (pathDesired.Mode == PATHDESIRED_MODE_ENDPOINT) { updateEndpointVelocity(); updateVtolDesiredAttitude(); } else { AlarmsSet(SYSTEMALARMS_ALARM_GUIDANCE,SYSTEMALARMS_ALARM_ERROR); } break; case FLIGHTSTATUS_FLIGHTMODE_PATHPLANNER: if (pathDesired.Mode == PATHDESIRED_MODE_ENDPOINT) { updateEndpointVelocity(); updateVtolDesiredAttitude(); } else if (pathDesired.Mode == PATHDESIRED_MODE_PATH) { updatePathVelocity(); updateVtolDesiredAttitude(); } else { AlarmsSet(SYSTEMALARMS_ALARM_GUIDANCE,SYSTEMALARMS_ALARM_ERROR); break; } break; default: // Be cleaner and get rid of global variables northVelIntegral = 0; eastVelIntegral = 0; downVelIntegral = 0; northPosIntegral = 0; eastPosIntegral = 0; downPosIntegral = 0; // Track throttle before engaging this mode. Cheap system ident StabilizationDesiredData stabDesired; StabilizationDesiredGet(&stabDesired); throttleOffset = stabDesired.Throttle; break; } } } /** * Compute desired velocity from the current position and path * * Takes in @ref PositionActual and compares it to @ref PathDesired * and computes @ref VelocityDesired */ static void updatePathVelocity() { float dT = guidanceSettings.UpdatePeriod / 1000.0f; float downCommand; PositionActualData positionActual; PositionActualGet(&positionActual); float cur[3] = {positionActual.North, positionActual.East, positionActual.Down}; struct path_status progress; path_progress(pathDesired.Start, pathDesired.End, cur, &progress); float groundspeed = pathDesired.StartingVelocity + (pathDesired.EndingVelocity - pathDesired.StartingVelocity) * progress.fractional_progress; if(progress.fractional_progress > 1) groundspeed = 0; VelocityDesiredData velocityDesired; velocityDesired.North = progress.path_direction[0] * groundspeed; velocityDesired.East = progress.path_direction[1] * groundspeed; float error_speed = progress.error * guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP]; float correction_velocity[2] = {progress.correction_direction[0] * error_speed, progress.correction_direction[1] * error_speed}; float total_vel = sqrtf(powf(correction_velocity[0],2) + powf(correction_velocity[1],2)); float scale = 1; if(total_vel > guidanceSettings.HorizontalVelMax) scale = guidanceSettings.HorizontalVelMax / total_vel; velocityDesired.North += progress.correction_direction[0] * error_speed * scale; velocityDesired.East += progress.correction_direction[1] * error_speed * scale; float altitudeSetpoint = pathDesired.Start[2] + (pathDesired.End[2] - pathDesired.Start[2]) * bound(progress.fractional_progress,0,1); float downError = altitudeSetpoint - positionActual.Down; downPosIntegral = bound(downPosIntegral + downError * dT * guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KI], -guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_ILIMIT], guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_ILIMIT]); downCommand = (downError * guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KP] + downPosIntegral); velocityDesired.Down = bound(downCommand, -guidanceSettings.VerticalVelMax, guidanceSettings.VerticalVelMax); VelocityDesiredSet(&velocityDesired); } /** * Compute desired velocity from the current position * * Takes in @ref PositionActual and compares it to @ref PositionDesired * and computes @ref VelocityDesired */ void updateEndpointVelocity() { float dT = guidanceSettings.UpdatePeriod / 1000.0f; PositionActualData positionActual; VelocityDesiredData velocityDesired; PositionActualGet(&positionActual); VelocityDesiredGet(&velocityDesired); float northError; float eastError; float downError; float northCommand; float eastCommand; float downCommand; float northPos = 0, eastPos = 0, downPos = 0; switch (guidanceSettings.PositionSource) { case VTOLPATHFOLLOWERSETTINGS_POSITIONSOURCE_EKF: northPos = positionActual.North; eastPos = positionActual.East; downPos = positionActual.Down; break; case VTOLPATHFOLLOWERSETTINGS_POSITIONSOURCE_GPSPOS: { NEDPositionData nedPosition; NEDPositionGet(&nedPosition); northPos = nedPosition.North; eastPos = nedPosition.East; downPos = nedPosition.Down; } break; default: PIOS_Assert(0); break; } // Compute desired north command northError = pathDesired.End[PATHDESIRED_END_NORTH] - northPos; northPosIntegral = bound(northPosIntegral + northError * dT * guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI], -guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT], guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]); northCommand = (northError * guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP] + northPosIntegral); eastError = pathDesired.End[PATHDESIRED_END_EAST] - eastPos; eastPosIntegral = bound(eastPosIntegral + eastError * dT * guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI], -guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT], guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]); eastCommand = (eastError * guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP] + eastPosIntegral); // Limit the maximum velocity float total_vel = sqrtf(powf(northCommand,2) + powf(eastCommand,2)); float scale = 1; if(total_vel > guidanceSettings.HorizontalVelMax) scale = guidanceSettings.HorizontalVelMax / total_vel; velocityDesired.North = northCommand * scale; velocityDesired.East = eastCommand * scale; downError = pathDesired.End[PATHDESIRED_END_DOWN] - downPos; downPosIntegral = bound(downPosIntegral + downError * dT * guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KI], -guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_ILIMIT], guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_ILIMIT]); downCommand = (downError * guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KP] + downPosIntegral); velocityDesired.Down = bound(downCommand, -guidanceSettings.VerticalVelMax, guidanceSettings.VerticalVelMax); VelocityDesiredSet(&velocityDesired); } /** * Compute desired attitude from the desired velocity * * Takes in @ref NedActual which has the acceleration in the * NED frame as the feedback term and then compares the * @ref VelocityActual against the @ref VelocityDesired */ static void updateVtolDesiredAttitude() { float dT = guidanceSettings.UpdatePeriod / 1000.0f; VelocityDesiredData velocityDesired; VelocityActualData velocityActual; StabilizationDesiredData stabDesired; AttitudeActualData attitudeActual; NedAccelData nedAccel; VtolPathFollowerSettingsData guidanceSettings; StabilizationSettingsData stabSettings; SystemSettingsData systemSettings; float northError; float northCommand; float eastError; float eastCommand; float downError; float downCommand; SystemSettingsGet(&systemSettings); VtolPathFollowerSettingsGet(&guidanceSettings); VelocityActualGet(&velocityActual); VelocityDesiredGet(&velocityDesired); StabilizationDesiredGet(&stabDesired); VelocityDesiredGet(&velocityDesired); AttitudeActualGet(&attitudeActual); StabilizationSettingsGet(&stabSettings); NedAccelGet(&nedAccel); float northVel = 0, eastVel = 0, downVel = 0; switch (guidanceSettings.VelocitySource) { case VTOLPATHFOLLOWERSETTINGS_VELOCITYSOURCE_EKF: northVel = velocityActual.North; eastVel = velocityActual.East; downVel = velocityActual.Down; break; case VTOLPATHFOLLOWERSETTINGS_VELOCITYSOURCE_NEDVEL: { GPSVelocityData gpsVelocity; GPSVelocityGet(&gpsVelocity); northVel = gpsVelocity.North; eastVel = gpsVelocity.East; downVel = gpsVelocity.Down; } break; case VTOLPATHFOLLOWERSETTINGS_VELOCITYSOURCE_GPSPOS: { GPSPositionData gpsPosition; GPSPositionGet(&gpsPosition); northVel = gpsPosition.Groundspeed * cosf(gpsPosition.Heading * F_PI / 180.0f); eastVel = gpsPosition.Groundspeed * sinf(gpsPosition.Heading * F_PI / 180.0f); downVel = velocityActual.Down; } break; default: PIOS_Assert(0); break; } // Testing code - refactor into manual control command ManualControlCommandData manualControlData; ManualControlCommandGet(&manualControlData); stabDesired.Yaw = stabSettings.MaximumRate[STABILIZATIONSETTINGS_MAXIMUMRATE_YAW] * manualControlData.Yaw; // Compute desired north command northError = velocityDesired.North - northVel; northVelIntegral = bound(northVelIntegral + northError * dT * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], -guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT], guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]); northCommand = (northError * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP] + northVelIntegral - nedAccel.North * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KD] + velocityDesired.North * guidanceSettings.VelocityFeedforward); // Compute desired east command eastError = velocityDesired.East - eastVel; eastVelIntegral = bound(eastVelIntegral + eastError * dT * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], -guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT], guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]); eastCommand = (eastError * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP] + eastVelIntegral - nedAccel.East * guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KD] + velocityDesired.East * guidanceSettings.VelocityFeedforward); // Compute desired down command downError = velocityDesired.Down - downVel; // Must flip this sign downError = -downError; downVelIntegral = bound(downVelIntegral + downError * dT * guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KI], -guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_ILIMIT], guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_ILIMIT]); downCommand = (downError * guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KP] + downVelIntegral - nedAccel.Down * guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KD]); stabDesired.Throttle = bound(downCommand + throttleOffset, 0, 1); // Project the north and east command signals into the pitch and roll based on yaw. For this to behave well the // craft should move similarly for 5 deg roll versus 5 deg pitch stabDesired.Pitch = bound(-northCommand * cosf(attitudeActual.Yaw * M_PI / 180) + -eastCommand * sinf(attitudeActual.Yaw * M_PI / 180), -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch); stabDesired.Roll = bound(-northCommand * sinf(attitudeActual.Yaw * M_PI / 180) + eastCommand * cosf(attitudeActual.Yaw * M_PI / 180), -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch); if(guidanceSettings.ThrottleControl == VTOLPATHFOLLOWERSETTINGS_THROTTLECONTROL_FALSE) { // For now override throttle with manual control. Disable at your risk, quad goes to China. ManualControlCommandData manualControl; ManualControlCommandGet(&manualControl); stabDesired.Throttle = manualControl.Throttle; } stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_ROLL] = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE; stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_PITCH] = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE; stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] = STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK; StabilizationDesiredSet(&stabDesired); } /** * Keep a running filtered version of the acceleration in the NED frame */ static void updateNedAccel() { float accel[3]; float q[4]; float Rbe[3][3]; float accel_ned[3]; // Collect downsampled attitude data AccelsData accels; AccelsGet(&accels); accel[0] = accels.x; accel[1] = accels.y; accel[2] = accels.z; //rotate avg accels into earth frame and store it AttitudeActualData attitudeActual; AttitudeActualGet(&attitudeActual); q[0]=attitudeActual.q1; q[1]=attitudeActual.q2; q[2]=attitudeActual.q3; q[3]=attitudeActual.q4; Quaternion2R(q, Rbe); for (uint8_t i=0; i<3; i++){ accel_ned[i]=0; for (uint8_t j=0; j<3; j++) accel_ned[i] += Rbe[j][i]*accel[j]; } accel_ned[2] += 9.81f; NedAccelData accelData; NedAccelGet(&accelData); accelData.North = accel_ned[0]; accelData.East = accel_ned[1]; accelData.Down = accel_ned[2]; NedAccelSet(&accelData); } /** * Bound input value between limits */ static float bound(float val, float min, float max) { if (val < min) { val = min; } else if (val > max) { val = max; } return val; } static void SettingsUpdatedCb(UAVObjEvent * ev) { VtolPathFollowerSettingsGet(&guidanceSettings); PathDesiredGet(&pathDesired); }