SL_SEQ #

Brief #

The sl_seq component starts a motor without an encoder and hands it to the observer (obs), for a PMSM and an induction motor alike.

States #

0. off: en = 0. Everything reset, obs tracks.
1. align: current i_f on d at a standing frame for align_time. PMSM: the rotor turns onto the d axis. Induction motor: the flux builds (about 3 tr, what align_time 0 uses).
2. I/f: the frame turns at f, which ramps toward vel_cmd at acc, with i_f on d. The rotor follows the rotating current. obs tracks the frame below w_hand / 2, so it starts with the right direction, then runs free.
3. observer: angle0 from obs (src 2), d and q from the drive (d_in, q_in, pmsm_ttc0 or acim_foc0), pid_en = 1, pid closes the speed loop on obs0.vel_m, while d goes from i_f to d_in over fade_time so the current does not step. Entered once obs is ok, |f| >= w_hand and obs ran free lock_time. Back to 2 when obs drops ok or |obs0.vel_m| < w_hand - hyst, with f seeded from obs0.vel_m.

vel_ref and acc_ref replace the command into pid: they follow f in I/f and, from the handover, ramp from the observed speed to vel_cmd at acc, so the handover is bumpless and pid gets acceleration feedforward.

Encoder plausibility guard (optional, enc_tol > 0, needs vel_enc from an encoder with the same sign and scale as obs0.vel_m, e.g. a spindle orientation encoder). The tolerance is enc_tol times the slip model’s own limit, slip_max (acim_flux0.slip_max, electrical) / polecount, so about 1 fits any motor: in I/f the frequency stays within it of the encoder speed, so a rotor that does not follow is not left behind. In state 3 an observer speed further than it from the encoder for enc_time falls back to I/f, seeded from the encoder, and sets enc_err (link it to a fault input to trip instead). Steady, slip_err is the slip model’s error, a check on acim_flux0.tr without the MRAS (the sl_acim template links it to acim_flux0.slip_err, for tr_ks). Outside state 3 there is no observer speed to compare, so slip_err is held at 0 and tr_ks does not adapt on the last value. enc_tol 0 = off.

Defaults from the motor (each 0 = derived, a value set in the config wins):

• align_time 0 = 3 * tr (acim_flux0.tr: the flux has built), 0.3 s without tr (PMSM: the rotor has turned onto d).
• w_hand 0 = the speed where the emf is 5 * e_min (obs0.e_min, the observer’s own trust level): 5 * e_min / (polecount * flux), flux = psi (conf0.psi, PMSM) or lmr * i_f (acim_flux0.lmr, induction motor after align). 50 rad/s without either.
• obs_bw = 5 * hand * polecount, the observer bandwidth. The sl_acim template links obs0.bw to it (it used to be set by hand, spindle 300); an obs0.bw in the config wins.

Speeds are mechanical rad/s. vel_e is f * polecount.

Low speed: below w_hand - hyst the drive is in I/f, with no speed loop and no torque control, so that is the lowest closed loop speed. w_hand belongs where the emf, w_hand * polecount * lmr * i_f (PMSM: psi), is about 5 times obs0.e_min, which is what w_hand 0 derives; the sl_acim template links i_f to acim_foc0.id_n, so the induction motor’s flux is the rated one.

Pins #

References #

Source: .c File