aos/common/controls/control_loop-tmpl.h

#include <stddef.h>
#include <inttypes.h>

#include "aos/common/logging/logging.h"
#include "aos/common/messages/robot_state.q.h"
#include "aos/common/logging/queue_logging.h"
#include "aos/common/util/phased_loop.h"

namespace aos {
namespace controls {

// TODO(aschuh): Tests.

template <class T>
constexpr ::aos::time::Time ControlLoop<T>::kStaleLogInterval;
template <class T>
constexpr ::aos::time::Time ControlLoop<T>::kPwmDisableTime;

template <class T>
void ControlLoop<T>::ZeroOutputs() {
  aos::ScopedMessagePtr<OutputType> output =
      control_loop_->output.MakeMessage();
  Zero(output.get());
  output.Send();
}

template <class T>
void ControlLoop<T>::Iterate() {
  no_goal_.Print();
  driver_station_old_.Print();
  no_sensor_state_.Print();
  no_driver_station_.Print();
  motors_off_log_.Print();

  control_loop_->position.FetchAnother();
  const PositionType *const position = control_loop_->position.get();
  LOG_STRUCT(DEBUG, "position", *position);

  // Fetch the latest control loop goal. If there is no new
  // goal, we will just reuse the old one.
  // If there is no goal, we haven't started up fully.  It isn't worth
  // the added complexity for each loop implementation to handle that case.
  control_loop_->goal.FetchLatest();
  // TODO(aschuh): Check the age here if we want the loop to stop on old
  // goals.
  const GoalType *goal = control_loop_->goal.get();
  if (goal) {
    LOG_STRUCT(DEBUG, "goal", *goal);
  } else {
    LOG_INTERVAL(no_goal_);
  }

  ::aos::robot_state.FetchLatest();
  if (!::aos::robot_state.get()) {
    LOG_INTERVAL(no_sensor_state_);
    return;
  }
  if (sensor_reader_pid_ != ::aos::robot_state->reader_pid) {
    LOG(INFO, "new sensor reader PID %" PRId32 ", old was %" PRId32 "\n",
        ::aos::robot_state->reader_pid, sensor_reader_pid_);
    reset_ = true;
    sensor_reader_pid_ = ::aos::robot_state->reader_pid;
  }

  bool outputs_enabled = false;

  // Check to see if we got a driver station packet recently.
  if (::aos::joystick_state.FetchLatest()) {
    if (::aos::joystick_state->enabled) outputs_enabled = true;
    if (::aos::robot_state->outputs_enabled) {
      // If the driver's station reports being disabled, we're probably not
      // actually going to send motor values regardless of what the FPGA
      // reports.
      if (::aos::joystick_state->enabled) {
        last_pwm_sent_ = ::aos::robot_state->sent_time;
      } else {
        LOG(WARNING, "outputs enabled while disabled\n");
      }
    } else if (::aos::joystick_state->enabled) {
      LOG(WARNING, "outputs disabled while enabled\n");
    }
  } else if (::aos::joystick_state.IsNewerThanMS(kDSPacketTimeoutMs) &&
             ::aos::joystick_state->enabled) {
    outputs_enabled = true;
  } else {
    if (::aos::joystick_state.get()) {
      LOG_INTERVAL(driver_station_old_);
    } else {
      LOG_INTERVAL(no_driver_station_);
    }
  }

  // The 100ms is the result of using an oscilliscope to look at the PWM signal
  // and output of a talon, and timing the delay between the last pulse and the
  // talon turning off.
  const bool motors_off =
      (::aos::time::Time::Now() - last_pwm_sent_) >= kPwmDisableTime;
  if (motors_off) {
    if (::aos::joystick_state.get() && ::aos::joystick_state->enabled) {
      LOG_INTERVAL(motors_off_log_);
    }
    outputs_enabled = false;
  }

  aos::ScopedMessagePtr<StatusType> status =
      control_loop_->status.MakeMessage();
  if (status.get() == nullptr) {
    return;
  }

  if (outputs_enabled) {
    aos::ScopedMessagePtr<OutputType> output =
        control_loop_->output.MakeMessage();
    RunIteration(goal, position, output.get(), status.get());

    LOG_STRUCT(DEBUG, "output", *output);
    output.Send();
  } else {
    // The outputs are disabled, so pass nullptr in for the output.
    RunIteration(goal, position, nullptr, status.get());
    ZeroOutputs();
  }

  LOG_STRUCT(DEBUG, "status", *status);
  status.Send();
}

template <class T>
void ControlLoop<T>::Run() {
  while (true) {
    Iterate();
  }
}

}  // namespace controls
}  // namespace aos