-#!/bin/bash
-
-#==BEGIN function definition==
-yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
-die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
-try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
-update_pi() {
- # Desc: Calculates control variable (CV) given setpoint (SP) and
- # process variable (PV). Uses proportional integral (PI)
- # control.
- # Usage: update_pi arg1 arg2 arg3 arg4 arg5 arg6
- # Version: 0.1.3
- # Input: arg1: path_loop_name (control loop name path)
- # arg2: var_pv (process variable)
- # arg3: var_sp (set point)
- # arg4: tune_p (proportional tuning factor)
- # arg5: tune_i (integral tuning factor)
- # arg6: var_cv_bias (control variable bias; prevents initial jerk)
- # Output: stdout: var_cv (control variable)
- # file: path_var_pv
- # file: path_var_sp
- # file: path_tune_p
- # file: path_tune_i
- # file: path_var_cv
- # file: path_sum (saves updated sum state)
- # Example: update_pi /dev/shm/DC1.AC 1.0 3.0 2.0 3.0
- # Depends: bc, gnu coreutils 8.30, yell(), try()
- local var_sp var_pv var_cv;
- local tune_p tune_i;
- local term_p term_i;
- local error sum sum_cand;
- local path_sum path_var_sp path_var_pv path_tune_p path_tune_i;
-
- path_loop_name="$1";
-
- path_var_pv="$path_loop_name".pv
- var_pv="$2"; # read provided process variable
-
- path_var_sp="$path_loop_name".sp
- if [[ -f "$path_var_sp" ]]; then
- var_sp="$(cat "$path_var_sp" | head -n1)";
- else
- var_sp="$3";
- fi;
-
- path_tune_p="$path_loop_name".tune_p
- if [[ -f "$path_tune_p" ]]; then
- tune_p="$(cat "$path_tune_p" | head -n1)";
- else
- tune_p="$4";
- fi;
-
- path_tune_i="$path_loop_name".tune_i
- if [[ -f "$path_tune_i" ]]; then
- tune_i="$(cat "$path_tune_i" | head -n1)";
- else
- tune_i="$5";
- fi;
-
- path_var_cv="$path_loop_name".cv
-
- path_var_cv_bias="$path_loop_name".cv_bias
- var_cv_bias="$6";
-
- path_sum="$path_loop_name".sum
- if [[ -f "$path_sum" ]]; then
- sum="$(cat "$path_sum" | head -n1)";
- else
- sum=0;
- fi;
-
- #yell "DEBUG:path_loop_name:$path_loop_name";
- #yell "DEBUG:var_pv:$var_pv";
- #yell "DEBUG:var_sp:$var_sp";
- #yell "DEBUG:var_cv:$var_cv";
- #yell "DEBUG:var_cv_bias:$var_cv_bias";
- #yell "DEBUG:tune_p:$tune_p";
- #yell "DEBUG:tune_i:$tune_i";
-
- error="$(try echo "$var_sp - $var_pv" | bc -l)";
- #yell "DEBUG:error:$error";
- sum_cand="$(try echo "$sum + $error" | bc -l)";
- #yell "DEBUG:sum:$sum";
- if [[ "$(try echo "$sum_cand > 2 * $sum " | bc -l)" -eq 1 ]]; then
- sum="$(try echo "$sum + l($error + 1)" | bc -l)"; # dampen integral sum spikes
- else
- sum="$sum_cand";
- fi;
- term_p="$(try echo "$tune_p * $error" | bc -l)";
- #yell "DEBUG:term_p:$term_p";
- term_i="$(try echo "$tune_i * $sum" | bc -l)";
- #yell "DEBUG:term_i:$term_i";
- var_cv="$(try echo "$term_p + $term_i + $var_cv_bias" | bc -l)";
- #yell "DEBUG:var_cv:$var_cv";
-
- # Write variables to memory
- echo "$sum" > "$path_sum";
- echo "$var_sp" > "$path_var_sp";
- echo "$var_pv" > "$path_var_pv";
- echo "$tune_p" > "$path_tune_p";
- echo "$tune_i" > "$path_tune_i";
- echo "$var_cv" > "$path_var_cv";
- echo "$var_cv_bias" > "$path_var_cv_bias";
-
- # Output control variable to stdout
- echo "$var_cv";
-
- #yell "DEBUG:=============END_ROUND===============";
-} # update specified PI loop
-#==END function definition==
-
-#==BEGIN Example code==
-path_loop_name="/tmp/DC1.AC";
-var_pv=1.0;
-var_sp=2.0;
-tune_p=1.0;
-tune_i=0.1;
-var_cv_init=1000;
-try rm "$path_loop_name"*
-
-var_pv=4.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=4.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=4.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=4.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=4.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=1.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=1.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=1.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-var_pv=1.0;
-output="$(update_pi "$path_loop_name" "$var_pv" "$var_sp" "$tune_p" "$tune_i" "$var_cv_init" | tail -n1)";
-yell "DEBUG:sum:$(cat "$path_loop_name".sum | head -n1)";
-yell "DEBUG:output:$output";
-#==END Example code==
-
-# Author: Steven Baltakatei Sandoval
-# License: GPLv3+
projects / BK-2020-03.git / blobdiff