mirror of
https://gitee.com/mirrors_PX4/PX4-Autopilot.git
synced 2026-07-06 03:10:35 +08:00
Dennis Mannhart
88 lines
3.3 KiB
C++
88 lines
3.3 KiB
C++
/****************************************************************************
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*
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* Copyright (c) 2019 PX4 Development Team. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name PX4 nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/**
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* @file TrajMath.hpp
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*
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* collection of functions used in trajectory generators
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*/
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#pragma once
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namespace trajmath
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{
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/* Compute the maximum possible speed on the track given the remaining distance,
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* the maximum acceleration and the maximum jerk.
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* We assume a constant acceleration profile with a delay of 2*accel/jerk
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* (time to reach the desired acceleration from opposite max acceleration)
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* Equation to solve: 0 = vel^2 - 2*accel*(x - vel*2*accel/jerk)
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*
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* @param jerk maximum jerk
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* @param accel maximum acceleration
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* @param braking_distance distance to the desired stopping point
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*
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* @return maximum speed
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*/
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float computeMaxSpeedFromBrakingDistance(const float jerk, const float accel, const float braking_distance)
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{
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float b = 4.0f * accel * accel / jerk;
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float c = - 2.0f * accel * braking_distance;
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float max_speed = 0.5f * (-b + sqrtf(b * b - 4.0f * c));
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return max_speed;
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}
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/* Compute the maximum tangential speed in a circle defined by two line segments of length "d"
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* forming a V shape, opened by an angle "alpha". The circle is tangent to the end of the
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* two segments as shown below:
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* \\
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* | \ d
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* / \
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* __='___a\
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* d
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* @param alpha angle between the two line segments
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* @param accel maximum lateral acceleration
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* @param d length of the two line segments
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*
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* @return maximum tangential speed
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*/
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float computeMaxSpeedInWaypoint(const float alpha, const float accel, const float d)
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{
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float tan_alpha = tanf(alpha / 2.0f);
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float max_speed_in_turn = sqrtf(accel * d * tan_alpha);
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return max_speed_in_turn;
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}
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} /* namespace trajmath */
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