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Reduce noise on coarse detents

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This commit is contained in:
Scott Bezek
2022-01-16 11:24:57 -08:00
parent b92b805e13
commit 723396f588
3 changed files with 28 additions and 5 deletions
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3
firmware/src/display_task.cpp
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@@ -73,13 +73,16 @@ static void HSV_to_RGB(float h, float s, float v, uint8_t *r, uint8_t *g, uint8_
}
void DisplayTask::run() {
delay(100);
tft_.begin();
tft_.invertDisplay(1);
tft_.setRotation(0);
tft_.fillScreen(TFT_PURPLE);
spr_.setColorDepth(16);
if (spr_.createSprite(TFT_WIDTH, TFT_HEIGHT) == nullptr) {
Serial.println("ERROR: sprite allocation failed!");
tft_.fillScreen(TFT_RED);
}
spr_.setTextColor(0xFFFF, TFT_BLACK);

6
firmware/src/interface_task.cpp
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@@ -40,9 +40,9 @@ static KnobConfig configs[] = {
{
2,
0,
45 * PI / 180,
60 * PI / 180,
1,
0.6, // Note the snap point is slightly past the midpoint (0.5); compare to normal detents which use a snap point *past* the next value (i.e. > 1)
0.55, // Note the snap point is slightly past the midpoint (0.5); compare to normal detents which use a snap point *past* the next value (i.e. > 1)
"On/off\nStrong detent",
},
{
@@ -81,7 +81,7 @@ static KnobConfig configs[] = {
32,
0,
8.225806452 * PI / 180,
0.1,
0.2,
1.1,
"Coarse values\nWeak detents",
},

24
firmware/src/motor_task.cpp
View File

@@ -104,6 +104,25 @@ void MotorTask::run() {
if (xQueueReceive(queue_, &config, 0) == pdTRUE) {
Serial.println("Got new config");
current_detent_center = motor.shaft_angle;
// Update derivative factor of torque controller based on detent width.
// If the D factor is large on coarse detents, the motor ends up making noise because the P&D factors amplify the noise from the sensor.
// This is a piecewise linear function so that fine detents (small width) get a higher D factor and coarse detents get a small D factor.
// Fine detents need a nonzero D factor to artificially create "clicks" each time a new value is reached (the P factor is small
// for fine detents due to the smaller angular errors, and the existing P factor doesn't work well for very small angle changes (easy to
// get runaway due to sensor noise & lag)).
// TODO: consider eliminating this D factor entirely and just "play" a hardcoded haptic "click" (e.g. a quick burst of torque in each
// direction) whenever the position changes when the detent width is too small for the P factor to work well.
const float derivative_lower_strength = config.detent_strength_unit * 0.06;
const float derivative_upper_strength = config.detent_strength_unit * 0;
const float derivative_position_width_lower = 5 * PI / 180;
const float derivative_position_width_upper = 10 * PI / 180;
const float raw = derivative_lower_strength + (derivative_upper_strength - derivative_lower_strength)/(derivative_position_width_upper - derivative_position_width_lower)*(config.position_width_radians - derivative_position_width_lower);
motor.PID_velocity.D = CLAMP(
raw,
min(derivative_lower_strength, derivative_upper_strength),
max(derivative_lower_strength, derivative_upper_strength)
);
}
idle_check_velocity_ewma = motor.shaft_velocity * IDLE_VELOCITY_EWMA_ALPHA + idle_check_velocity_ewma * (1 - IDLE_VELOCITY_EWMA_ALPHA);
@@ -144,9 +163,10 @@ void MotorTask::run() {
fminf(config.position_width_radians*DEAD_ZONE_DETENT_PERCENT, DEAD_ZONE_RAD));
bool out_of_bounds = config.num_positions > 0 && ((angle_to_detent_center > 0 && config.position == 0) || (angle_to_detent_center < 0 && config.position == config.num_positions - 1));
motor.PID_velocity.limit = out_of_bounds ? 10 : 3;
motor.PID_velocity.limit = 10; //out_of_bounds ? 10 : 3;
motor.PID_velocity.P = out_of_bounds ? 4 : config.detent_strength_unit * 4;
motor.PID_velocity.D = config.detent_strength_unit * 0.02;
if (fabsf(motor.shaft_velocity) > 20) {
// Don't apply torque if velocity is too high (helps avoid positive feedback loop/runaway)