/* * This file is part of the moving_model project. * Copyright 2025 Edward V. Emelianov . * * 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 . */ // simplest trapezioidal ramp #include #include #include #include #include "Tramp.h" #undef DBG #define DBG(...) static movestate_t state = ST_STOP; static moveparam_t Min, Max; // `Min` acceleration not used! typedef enum{ STAGE_ACCEL, // start from zero speed and accelerate to Max speed STAGE_MAXSPEED, // go with target speed STAGE_DECEL, // go from target speed to zero STAGE_STOPPED, // stop STAGE_AMOUNT } movingstage_t; static movingstage_t movingstage = STAGE_STOPPED; static double Times[STAGE_AMOUNT] = {0}; // time when each stage starts static moveparam_t Params[STAGE_AMOUNT] = {0}; // starting parameters for each stage static moveparam_t curparams = {0}; // current coordinate/speed/acceleration static int initlims(limits_t *lim){ if(!lim) return FALSE; Min = lim->min; Max = lim->max; return TRUE; } static void emstop(double _U_ t){ curparams.accel = 0.; curparams.speed = 0.; bzero(Times, sizeof(Times)); bzero(Params, sizeof(Params)); state = ST_STOP; movingstage = STAGE_STOPPED; } static void stop(double t){ if(state == ST_STOP || movingstage == STAGE_STOPPED) return; movingstage = STAGE_DECEL; state = ST_MOVE; Times[STAGE_DECEL] = t; Params[STAGE_DECEL].speed = curparams.speed; if(curparams.speed > 0.) Params[STAGE_DECEL].accel = -Max.accel; else Params[STAGE_DECEL].accel = Max.accel; Params[STAGE_DECEL].coord = curparams.coord; // speed: v=v2+a2(t-t2), v2 and a2 have different signs; t3: v3=0 -> t3=t2-v2/a2 Times[STAGE_STOPPED] = t - curparams.speed / Params[STAGE_DECEL].accel; // coordinate: x=x2+v2(t-t2)+a2(t-t2)^2/2 -> x3=x2+v2(t3-t2)+a2(t3-t2)^2/2 double dt = Times[STAGE_STOPPED] - t; Params[STAGE_STOPPED].coord = curparams.coord + curparams.speed * dt + Params[STAGE_DECEL].accel * dt * dt / 2.; } /** * @brief calc - moving calculation * @param x - using max speed (>0!!!) and coordinate * @param t - current time value * @return FALSE if can't move with given parameters */ static int calc(moveparam_t *x, double t){ if(!x) return FALSE; if(x->coord < Min.coord || x->coord > Max.coord) return FALSE; if(x->speed < Min.speed || x->speed > Max.speed) return FALSE; double Dx = fabs(x->coord - curparams.coord); // full distance double sign = (x->coord > curparams.coord) ? 1. : -1.; // sign of target accelerations and speeds // we have two variants: with or without stage with constant speed double dt23 = x->speed / Max.accel; // time of deceleration stage for given speed double dx23 = x->speed * dt23 / 2.; // distance on dec stage (abs) DBG("Dx=%g, sign=%g, dt23=%g, dx23=%g", Dx, sign, dt23, dx23); double setspeed = x->speed; // new max speed (we can change it if need) double dt01, dx01; // we'll fill them depending on starting conditions Times[0] = t; Params[0].speed = curparams.speed; Params[0].coord = curparams.coord; double curspeed = fabs(curparams.speed); double dt0s = curspeed / Max.accel; // time of stopping phase double dx0s = curspeed * dt0s / 2.; // distance DBG("dt0s=%g, dx0s=%g", dt0s, dx0s); if(dx0s > Dx){ WARNX("distance too short"); return FALSE; } if(fabs(Dx - dx0s) < coord_tolerance){ // just stop and we'll be on target DBG("Distance good to just stop"); stop(t); return TRUE; } if(curparams.speed * sign < 0. || state == ST_STOP){ // we should change speed sign // after stop we will have full profile double dxs3 = Dx - dx0s; double newspeed = sqrt(Max.accel * dxs3); if(newspeed < setspeed) setspeed = newspeed; // we can't reach user speed DBG("dxs3=%g, setspeed=%g", dxs3, setspeed); dt01 = fabs(sign*setspeed - curparams.speed) / Max.accel; Params[0].accel = sign * Max.accel; if(state == ST_STOP) dx01 = setspeed * dt01 / 2.; else dx01 = dt01 * (dt01 / 2. * Max.accel - curspeed); DBG("dx01=%g, dt01=%g", dx01, dt01); }else{ // increase or decrease speed without stopping phase dt01 = fabs(sign*setspeed - curparams.speed) / Max.accel; double a = sign * Max.accel; if(sign * curparams.speed < 0.){DBG("change direction"); a = -a;} else if(curspeed > setspeed){ DBG("lower speed @ this direction"); a = -a;} //double a = (curspeed > setspeed) ? -Max.accel : Max.accel; dx01 = curspeed * dt01 + a * dt01 * dt01 / 2.; DBG("dt01=%g, a=%g, dx01=%g", dt01, a, dx01); if(dx01 + dx23 > Dx){ // calculate max speed setspeed = sqrt(Max.accel * Dx - curspeed * curspeed / 2.); if(setspeed < curspeed){ setspeed = curparams.speed; dt01 = 0.; dx01 = 0.; Params[0].accel = 0.; }else{ Params[0].accel = a; dt01 = fabs(setspeed - curspeed) / Max.accel; dx01 = curspeed * dt01 + Max.accel * dt01 * dt01 / 2.; } }else Params[0].accel = a; } if(setspeed < Min.speed){ WARNX("New speed should be too small"); return FALSE; } moveparam_t *p = &Params[STAGE_MAXSPEED]; p->accel = 0.; p->speed = sign * setspeed; p->coord = curparams.coord + dx01 * sign; Times[STAGE_MAXSPEED] = Times[0] + dt01; dt23 = setspeed / Max.accel; dx23 = setspeed * dt23 / 2.; // calculate dx12 and dt12 double dx12 = Dx - dx01 - dx23; if(dx12 < -coord_tolerance){ WARNX("Oops, WTF dx12=%g?", dx12); return FALSE; } double dt12 = dx12 / setspeed; p = &Params[STAGE_DECEL]; p->accel = -sign * Max.accel; p->speed = sign * setspeed; p->coord = Params[STAGE_MAXSPEED].coord + sign * dx12; Times[STAGE_DECEL] = Times[STAGE_MAXSPEED] + dt12; p = &Params[STAGE_STOPPED]; p->accel = 0.; p->speed = 0.; p->coord = x->coord; Times[STAGE_STOPPED] = Times[STAGE_DECEL] + dt23; for(int i = 0; i < 4; ++i) DBG("%d: t=%g, coord=%g, speed=%g, accel=%g", i, Times[i], Params[i].coord, Params[i].speed, Params[i].accel); state = ST_MOVE; movingstage = STAGE_ACCEL; return TRUE; } static movestate_t proc(moveparam_t *next, double t){ if(state == ST_STOP) goto ret; for(movingstage_t s = STAGE_STOPPED; s >= 0; --s){ if(Times[s] <= t){ // check time for current stage movingstage = s; break; } } if(movingstage == STAGE_STOPPED){ curparams.coord = Params[STAGE_STOPPED].coord; emstop(t); goto ret; } // calculate current parameters double dt = t - Times[movingstage]; double a = Params[movingstage].accel; double v0 = Params[movingstage].speed; double x0 = Params[movingstage].coord; curparams.accel = a; curparams.speed = v0 + a * dt; curparams.coord = x0 + v0 * dt + a * dt * dt / 2.; ret: if(next) *next = curparams; return state; } static movestate_t getst(moveparam_t *cur){ if(cur) *cur = curparams; return state; } static double gettstop(){ return Times[STAGE_STOPPED]; } movemodel_t trapez = { .init_limits = initlims, .stop = stop, .emergency_stop = emstop, .get_state = getst, .calculate = calc, .proc_move = proc, .stoppedtime = gettstop, };