PlatformGlobalTrajectoryController.h

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/**
 * This file is part of ArmarX.
 *
 * ArmarX is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * ArmarX 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, see <http://www.gnu.org/licenses/>.
 *
 * @author     Fabian Reister ( fabian dot reister at kit dot edu )
 * @date       2022
 * @copyright  http://www.gnu.org/licenses/gpl-2.0.txt
 *             GNU General Public License
 */
 
#pragma once
 
#include <atomic>
#include <cstdint>
#include <map>
#include <mutex>
#include <optional>
#include <string>
#include <vector>
 
#include <Ice/Current.h>
#include <Ice/Object.h>
#include <IceUtil/Time.h>
 
#include <VirtualRobot/VirtualRobot.h>
 
#include <ArmarXCore/interface/observers/ObserverInterface.h>
#include <ArmarXCore/util/CPPUtility/TripleBuffer.h>
 
#include <RobotAPI/components/units/RobotUnit/NJointControllers/NJointControllerBase.h>
#include <RobotAPI/components/units/RobotUnit/NJointControllers/NJointControllerWithTripleBuffer.h>
#include <RobotAPI/interface/aron/Aron.h>
#include <RobotAPI/interface/units/RobotUnit/NJointController.h>
#include <RobotAPI/interface/visualization/DebugDrawerInterface.h>
 
#include <armarx/control/interface/ConfigurableNJointControllerInterface.h>
#include <armarx/navigation/core/Trajectory.h>
#include <armarx/navigation/platform_controller/Diagnostics.h>
#include <armarx/navigation/trajectory_control/global/TrajectoryFollowingController.h>
 
namespace armarx
{
    class ControlTargetHolonomicPlatformVelocity;
    class SensorValueHolonomicPlatformVelocity;
    class SensorValueHolonomicPlatformWithAbsolutePosition;
} // namespace armarx
 
namespace armarx::navigation::platform_controller::platform_global_trajectory
{
    struct Targets
    {
        core::GlobalTrajectory trajectory;
    };
 
    struct Config
    {
        using Params = traj_ctrl::global::TrajectoryFollowingControllerParams;
 
        Params params;
        Targets targets;
        diagnostics::Params diagnostics;
    };
 
    struct Twist2D
    {
        Eigen::Vector2f linear = Eigen::Vector2f::Zero();
        float angular = 0;
 
        void
        reset()
        {
            linear = Eigen::Vector2f::Zero();
            angular = 0;
        }
    };
 
    using Target = Twist2D;
 
    struct Debug
    {
        Target target;
 
        double dropPointVelocity = 0;
        double currentOrientation = 0;
        double desiredOrientation = 0;
        double orientationError = 0;
        bool isFinalSegment = false;
 
        double positionError = 0;
 
        double ffAngular = 0;
        double cappedFfVel = 0;
 
        std::size_t projectionIndex = 0;
 
        bool angularFeedforwardSaturated = false;
 
        Eigen::Isometry3f global_T_robot = Eigen::Isometry3f::Identity();
    };
 
    struct Devices
    {
        ControlTargetHolonomicPlatformVelocity* platformTarget;
    };
 
    using NameValueMap = std::map<std::string, float>;
 
    class Controller :
        virtual public NJointControllerWithTripleBuffer<Target>,
        virtual public armarx::control::ConfigurableNJointControllerInterface
    {
    public:
        using ConfigPtrT = control::ConfigurableNJointControllerConfigPtr;
 
        Controller(const RobotUnitPtr& robotUnit,
                   const NJointControllerConfigPtr& config,
                   const VirtualRobot::RobotPtr&);
 
        ~Controller() override;
 
        std::string getClassName(const Ice::Current& iceCurrent = Ice::emptyCurrent) const override;
 
        void rtRun(const IceUtil::Time& sensorValuesTimestamp,
                   const IceUtil::Time& timeSinceLastIteration) override;
 
        void updateConfig(const ::armarx::aron::data::dto::DictPtr& dto,
                          const Ice::Current& iceCurrent = Ice::emptyCurrent) override;
 
        ::armarx::aron::data::dto::DictPtr
        getConfig(const ::Ice::Current& = ::Ice::emptyCurrent) override;
 
    protected:
        void additionalTask();
        void onPublish(const SensorAndControl& sac,
                       const DebugDrawerInterfacePrx& debugDrawer,
                       const DebugObserverInterfacePrx& debugObservers) override;
 
 
        void onInitNJointController() override;
        void rtPreActivateController() override;
        void rtPostDeactivateController() override;
 
        /// Walk `rtCommandedTwist` towards `target`, by at most the configured rate times `dt`.
        void rtSlewTowards(const Target& target, float dt);
 
        /// Record one control cycle. Runs on the 100 Hz task thread; no-op when disabled.
        void recordControlSample(
            const traj_ctrl::global::TrajectoryControllerResult& result,
            const Twist2D& commandedTwist,
            const core::GlobalTrajectory& trajectory,
            const traj_ctrl::global::TrajectoryFollowingControllerParams& params);
 
        /// Assemble and write the episode that just ended. Non-real-time; never throws.
        void writeDiagnosticsDump();
 
    private:
        struct RobotState
        {
            Eigen::Isometry3f global_T_robot;
 
            /// `sensorValuesTimestamp` of the cycle this pose was read in. The 100 Hz task has no
            /// clock of its own, and both diagnostics streams have to share one to be comparable.
            std::int64_t timestampUs = 0;
        };
 
        TripleBuffer<Config> configBuffer_updateConfigToAdditionalTask;
        TripleBuffer<Config> configBuffer_updateConfigToOnPublish;
 
        /// A separate arrow, per `NJointControllerBase`'s rule that each reader needs its own
        /// buffer: `getUpToDateReadBuffer()` is single-reader, and the diagnostics task reads the
        /// parameters into the dump's metadata while `onPublish` reads them for its datafields.
        TripleBuffer<Config> configBuffer_updateConfigToDiagnostics;
        TripleBuffer<Debug> targetBuffer_additionalTaskToOnPublish;
        TripleBuffer<RobotState> robotStateBuffer_rtToAdditionalTask;
 
 
        // internal
        std::atomic_bool rtFirstRun = true;
        std::atomic_bool rtReady = false;
 
        ControlTargetHolonomicPlatformVelocity* platformTarget;
 
        /// Seeds `rtCommandedTwist` on activation, so a controller switch while the base is
        /// moving does not start the slew from a velocity the robot does not have.
        const SensorValueHolonomicPlatformVelocity* platformSensor;
 
        std::optional<traj_ctrl::global::TrajectoryFollowingController>
            trajectoryFollowingController;
 
 
        Devices getDevices(const VirtualRobot::RobotNodeSet& rns);
 
        // additional task has exclusive access to this variable
        Twist2D filteredTwist;
 
        /// What was last written to the control target. RT thread only.
        Twist2D rtCommandedTwist;
 
        /**
         * @brief Upper bound on the `dt` the slew integrates, in seconds.
         *
         * The bound exists so the first cycle after an activation -- whose
         * `timeSinceLastIteration` can be however long the controller sat idle -- cannot let the
         * whole velocity step through at once.
         *
         * It is not a constant, because 2 ms is only a *guard* while the loop period is well
         * under it. On the real robot at 1 kHz that holds. `RobotUnitSimulation` runs the loop at
         * ~10 ms, where a 2 ms cap binds on every cycle instead and silently throttles the slew
         * to `rate * 2 ms / 10 ms`, i.e. a fifth of the configured acceleration -- measured at
         * 60 mm/s^2 against a configured 300, which is enough to overshoot a goal by 45 cm.
         *
         * Set once, in the constructor, from `RobotUnit::isSimulation()`. Read by the RT thread
         * only after that, so a plain float is sufficient.
         */
        float rtMaxSlewDeltaT{0.002F};
 
        /// Slew rates, mirrored out of the config so the RT thread never reads the config
        /// buffer. Written by `updateConfig` on an Ice thread, read every RT cycle.
        std::atomic<float> rtMaxLinearAcceleration{250.F};
        std::atomic<float> rtMaxAngularAcceleration{0.4F};
 
        /**
         * @brief Advanced by `additionalTask()` every time it publishes a twist.
         *
         * `rtRun()` keeps slewing towards whatever `rtGetControlStruct()` holds, and nothing else
         * tells it whether that value is still being produced. `RunningTaskBase::run()` wraps the
         * whole task callback in one try/catch, so a single escaping exception ended the 100 Hz
         * thread for good while the robot carried on executing the last twist -- a small linear
         * command in the *base* frame plus a yaw rate is a tight circle, i.e. a robot that turns
         * on the spot until someone stops it.
         */
        std::atomic<std::uint64_t> additionalTaskSequence{0};
 
        /// How many exceptions `additionalTask()` has swallowed. Published, so a controller that
        /// is silently failing every cycle is visible without the log.
        std::atomic<std::uint64_t> controlTaskExceptions{0};
 
        /// Set by the RT thread when the command it is executing has gone stale, read by
        /// `onPublish`. The RT thread must not log, so it only records.
        std::atomic<std::uint32_t> controlTargetStaleCycles{0};
 
        /// RT-thread-only: the sequence number last observed, and how long it has been unchanged.
        std::uint64_t rtLastSequence{0};
 
        float rtSecondsSinceTargetUpdate{0.F};
 
        /// `onPublish`-thread-only latch, so the stale warning is reported once per episode.
        bool publishedStaleWarning{false};
 
        // ------------------------------------------------------------------------------------ //
        // Diagnostics. Everything below is inert unless `diagnosticsParams_.enabled` was set in
        // the config the controller was *built* with -- the rings are sized once, in the
        // constructor, because the real-time thread writes into them.
        // ------------------------------------------------------------------------------------ //
 
        diagnostics::Params diagnosticsParams_;
 
        /// Whether the RobotUnit this runs against is simulated. Read once, in the constructor:
        /// it decides `rtMaxSlewDeltaT` and is recorded in every dump, because a reader cannot
        /// otherwise tell a 10 ms simulated loop from a 1 kHz real one.
        bool isSimulation_{false};
 
        /// Only for the dump's metadata -- the RobotUnit is not reachable from the task thread.
        std::string platformName_;
 
        diagnostics::Ring<diagnostics::RtSample> rtSamples_;
        diagnostics::Ring<diagnostics::ControlSample> controlSamples_;
 
        /// Bumped on every activation, stamped into every sample. Lets `snapshot()` separate one
        /// episode from the next without the ring ever being reset under a running reader.
        std::atomic<std::uint64_t> diagnosticsEpisode{0};
 
        /**
         * @brief Serviced by the 100 Hz task thread, which is the only place the file I/O may
         *        run: not the RT thread, not the shared publisher thread.
         *
         * Set from two places, because either alone loses records. Deactivation alone is not
         * enough: reaching the goal does not necessarily stop this controller -- the navigator's
         * `stop()` only deactivates one that reports active -- so an episode could end with its
         * data still sitting in the ring. A goal-reached request alone is not enough either: an
         * aborted or emergency-stopped run never reaches the goal.
         */
        std::atomic_bool diagnosticsDumpRequested{false};
 
        /// Whether a dump has already been written since the controller was last activated. Stops
        /// the deactivation that normally *follows* a goal-reached dump from writing a second,
        /// near-empty record for the handful of cycles in between.
        std::atomic_bool diagnosticsDumpedSinceActivation{false};
 
        /// `updateConfig`-thread only: the last `dumpRequest` observed, so only a change triggers.
        int lastDumpRequest{0};
 
        /// Bumped by `updateConfig`. `additionalTask` copies the trajectory whenever it changes,
        /// because the navigator replans during a request.
        std::atomic<std::uint64_t> trajectoryRevision{0};
 
        /// RT-thread-only: whether a slew bound was binding in the cycle just computed.
        bool rtSlewLimited{false};
 
        /// Guards the trajectory bookkeeping below, which the 100 Hz control task appends to and
        /// the diagnostics task takes away. Held around that bookkeeping only, never around the
        /// file I/O.
        std::mutex diagnosticsTrajectoryMutex;
 
        std::vector<diagnostics::TrajectoryRevision> recordedTrajectories;
        std::uint64_t lastRecordedTrajectoryRevision{0};
        std::uint64_t droppedTrajectoryRevisions{0};
 
        /// Cheap identity of the last trajectory recorded, so a config update that carries only a
        /// dump request does not append a duplicate of the trajectory already there.
        std::size_t lastRecordedTrajectorySize{0};
        Eigen::Vector3f lastRecordedTrajectoryEnd{Eigen::Vector3f::Zero()};
    };
 
} // namespace armarx::navigation::platform_controller::platform_global_trajectory