mirror of https://github.com/ArduPilot/ardupilot
112 lines
3.4 KiB
C++
112 lines
3.4 KiB
C++
/*
|
|
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, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "AP_OpticalFlow_MAV.h"
|
|
|
|
#if AP_OPTICALFLOW_MAV_ENABLED
|
|
|
|
#include <AP_HAL/AP_HAL.h>
|
|
#include <AP_AHRS/AP_AHRS.h>
|
|
|
|
#define OPTFLOW_MAV_TIMEOUT_SEC 0.5f
|
|
|
|
// detect the device
|
|
AP_OpticalFlow_MAV *AP_OpticalFlow_MAV::detect(AP_OpticalFlow &_frontend)
|
|
{
|
|
// we assume mavlink messages will be sent into this driver
|
|
AP_OpticalFlow_MAV *sensor = new AP_OpticalFlow_MAV(_frontend);
|
|
return sensor;
|
|
}
|
|
|
|
// read latest values from sensor and fill in x,y and totals.
|
|
void AP_OpticalFlow_MAV::update(void)
|
|
{
|
|
// record gyro values as long as they are being used
|
|
// the sanity check of dt below ensures old gyro values are not used
|
|
if (gyro_sum_count < 1000) {
|
|
const Vector3f& gyro = AP::ahrs().get_gyro();
|
|
gyro_sum.x += gyro.x;
|
|
gyro_sum.y += gyro.y;
|
|
gyro_sum_count++;
|
|
}
|
|
|
|
// return without updating state if no readings
|
|
if (count == 0) {
|
|
return;
|
|
}
|
|
|
|
struct AP_OpticalFlow::OpticalFlow_state state {};
|
|
|
|
state.surface_quality = quality_sum / count;
|
|
|
|
// calculate dt
|
|
const float dt = (latest_frame_us - prev_frame_us) * 1.0e-6;
|
|
prev_frame_us = latest_frame_us;
|
|
|
|
// sanity check dt
|
|
if (is_positive(dt) && (dt < OPTFLOW_MAV_TIMEOUT_SEC)) {
|
|
// calculate flow values
|
|
const float flow_scale_factor_x = 1.0f + 0.001f * _flowScaler().x;
|
|
const float flow_scale_factor_y = 1.0f + 0.001f * _flowScaler().y;
|
|
|
|
// copy flow rates to state structure
|
|
state.flowRate = { ((float)flow_sum.x / count) * flow_scale_factor_x * dt,
|
|
((float)flow_sum.y / count) * flow_scale_factor_y * dt };
|
|
|
|
// copy average body rate to state structure
|
|
state.bodyRate = { gyro_sum.x / gyro_sum_count, gyro_sum.y / gyro_sum_count };
|
|
|
|
// we only apply yaw to flowRate as body rate comes from AHRS
|
|
_applyYaw(state.flowRate);
|
|
} else {
|
|
// first frame received in some time so cannot calculate flow values
|
|
state.flowRate.zero();
|
|
state.bodyRate.zero();
|
|
}
|
|
|
|
_update_frontend(state);
|
|
|
|
// reset local buffers
|
|
flow_sum.zero();
|
|
quality_sum = 0;
|
|
count = 0;
|
|
|
|
// reset gyro sum
|
|
gyro_sum.zero();
|
|
gyro_sum_count = 0;
|
|
}
|
|
|
|
// handle OPTICAL_FLOW mavlink messages
|
|
void AP_OpticalFlow_MAV::handle_msg(const mavlink_message_t &msg)
|
|
{
|
|
mavlink_optical_flow_t packet;
|
|
mavlink_msg_optical_flow_decode(&msg, &packet);
|
|
|
|
// record time message was received
|
|
// ToDo: add jitter correction
|
|
latest_frame_us = AP_HAL::micros64();
|
|
|
|
// add sensor values to sum
|
|
flow_sum.x += packet.flow_x;
|
|
flow_sum.y += packet.flow_y;
|
|
quality_sum += packet.quality;
|
|
count++;
|
|
|
|
// take sensor id from message
|
|
sensor_id = packet.sensor_id;
|
|
}
|
|
|
|
#endif // AP_OPTICALFLOW_MAV_ENABLED
|