updates

test/pid-controller.test.js

@@ -0,0 +1,105 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const { PIDController, CascadePIDController } = require('../src/pid/index.js');
+
+test('pid supports freeze/unfreeze with held output', () => {
+  const pid = new PIDController({
+    kp: 2,
+    ki: 0.5,
+    kd: 0.1,
+    sampleTime: 100,
+    outputMin: 0,
+    outputMax: 100,
+  });
+
+  const t0 = Date.now();
+  const first = pid.update(10, 2, t0 + 100);
+  pid.freeze({ output: first, trackMeasurement: true });
+  const frozen = pid.update(10, 4, t0 + 200);
+  assert.equal(frozen, first);
+
+  pid.unfreeze();
+  const resumed = pid.update(10, 4, t0 + 300);
+  assert.equal(Number.isFinite(resumed), true);
+});
+
+test('pid supports dynamic tunings and gain scheduling', () => {
+  const pid = new PIDController({
+    kp: 1,
+    ki: 0,
+    kd: 0,
+    sampleTime: 100,
+    outputMin: -100,
+    outputMax: 100,
+    gainSchedule: [
+      { min: Number.NEGATIVE_INFINITY, max: 5, kp: 1, ki: 0, kd: 0 },
+      { min: 5, max: Number.POSITIVE_INFINITY, kp: 3, ki: 0, kd: 0 },
+    ],
+  });
+
+  const t0 = Date.now();
+  const low = pid.update(10, 9, t0 + 100, { gainInput: 4 });
+  const high = pid.update(10, 9, t0 + 200, { gainInput: 6 });
+
+  assert.equal(high > low, true);
+
+  const tuned = pid.update(10, 9, t0 + 300, { tunings: { kp: 10, ki: 0, kd: 0 } });
+  assert.equal(tuned > high, true);
+});
+
+test('pid applies deadband and output rate limits', () => {
+  const pid = new PIDController({
+    kp: 10,
+    ki: 0,
+    kd: 0,
+    deadband: 0.5,
+    sampleTime: 100,
+    outputMin: 0,
+    outputMax: 100,
+    outputRateLimitUp: 5,   // units per second
+    outputRateLimitDown: 5, // units per second
+  });
+
+  const t0 = Date.now();
+  const out1 = pid.update(10, 10, t0 + 100); // inside deadband -> no action
+  const out2 = pid.update(20, 0, t0 + 200);  // strong error but limited by rate
+
+  assert.equal(out1, 0);
+  // 5 units/sec * 0.1 sec = max 0.5 rise per cycle
+  assert.equal(out2 <= 0.5 + 1e-9, true);
+});
+
+test('cascade pid computes primary and secondary outputs', () => {
+  const cascade = new CascadePIDController({
+    primary: {
+      kp: 2,
+      ki: 0,
+      kd: 0,
+      sampleTime: 100,
+      outputMin: 0,
+      outputMax: 100,
+    },
+    secondary: {
+      kp: 1,
+      ki: 0,
+      kd: 0,
+      sampleTime: 100,
+      outputMin: 0,
+      outputMax: 100,
+    },
+  });
+
+  const t0 = Date.now();
+  const result = cascade.update({
+    setpoint: 10,
+    primaryMeasurement: 5,
+    secondaryMeasurement: 2,
+    timestamp: t0 + 100,
+  });
+
+  assert.equal(typeof result.primaryOutput, 'number');
+  assert.equal(typeof result.secondaryOutput, 'number');
+  assert.equal(result.primaryOutput > 0, true);
+  assert.equal(result.secondaryOutput > 0, true);
+});