fix: Removed erps lower limit.

Fixes small jerk during Smooth Startup.
emmebrusa · May 14, 2024 · d5335ac · d5335ac
1 parent cdee1d9
commit d5335ac
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Showing 5 changed files with 10 additions and 8 deletions.
diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
@@ -23,7 +23,7 @@ jobs:
  steps:
  - name: install SDCC
  run: | #install silent and then unpack missing installation libraries
- Invoke-WebRequest https://altushost-swe.dl.sourceforge.net/project/sdcc/sdcc-win64/$env:SDCC_VERSION/sdcc-$env:SDCC_VERSION-x64-setup.exe -OutFile sdcc_setup.exe
+ Invoke-WebRequest https://netix.dl.sourceforge.net/project/sdcc/sdcc-win64/$env:SDCC_VERSION/sdcc-$env:SDCC_VERSION-x64-setup.exe -OutFile sdcc_setup.exe
  Start-Process -wait -FilePath "sdcc_setup.exe" -ArgumentList "/S", "/D=C:\Program Files\SDCC"
  - uses: actions/checkout@v2
  - name: Build

diff --git a/src/controller/ebike_app.c b/src/controller/ebike_app.c
@@ -832,7 +832,7 @@ static void apply_smooth_start(void){
 
  //voltage based control assumes the winding resistance is constant for simplicity
  uint32_t smooth_start_voltage_target_x100 = (uint32_t)(uint16_t)(smooth_start_voltage_limit_x100 + smooth_start_voltage_limit_blend_x100);
- smooth_start_voltage_target_x100 += (uint32_t)(uint16_t)(ui16_motor_bemf_voltage_x1000 / (10U + SMOOTH_START_BEMF_REDUCE_FACTOR));
+ smooth_start_voltage_target_x100 += (uint32_t)(uint16_t)(ui16_motor_bemf_voltage_x1000 / (10U + SMOOTH_START_BEMF_REDUCE_FACTOR));//due to resolution of the pwm duty cycle, BEMF starts to increase the duty effectively only above about 3erps
  if (smooth_start_voltage_target_x100 > UINT16_MAX){
  smooth_start_voltage_target_x100 = UINT16_MAX;
  }

diff --git a/src/controller/main.h b/src/controller/main.h
@@ -16,9 +16,11 @@
 
 // PWM related values
 // motor
-#define PWM_CYCLES_SECOND 19047U // 52us (PWM period)
-#define PWM_CYCLES_COUNTER_MAX 3800U // 5 erps minimum speed -> 1/5 = 200 ms; 200 ms / 50 us = 4000 (3125 at 15.625KHz)
-#define DOUBLE_PWM_CYCLES_SECOND 38094 // 25us (2 irq x PWM period)
+#define PWM_PERIOD 420U
+#define PWM_DOUBLE_PERIOD (2U*PWM_PERIOD) //PWM center aligned mode: counts from 0 to PWM_PERIOD and then down from PWM_PERIOD to 0
+#define PWM_CYCLES_SECOND ((uint16_t)(HSE_VALUE / PWM_DOUBLE_PERIOD)) // 19047Hz - 52us (PWM period) - !! has to be less than 21845
+#define DOUBLE_PWM_CYCLES_SECOND ((uint16_t)(HSE_VALUE / PWM_PERIOD)) // 25us (2 irq x PWM period)
+#define PWM_CYCLES_COUNTER_MAX (DOUBLE_PWM_CYCLES_SECOND + 1U) // +1U ensures ui16_motor_speed_erps is 0 when counter is max
 // ramp up/down PWM cycles count
 #define PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP_CADENCE_OFFSET 60 // PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP offset for cadence assist mode
 //#define PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP_DEFAULT 195 // 160 -> 160 * 64 us for every duty cycle increment at 15.625KHz

diff --git a/src/controller/motor.c b/src/controller/motor.c
@@ -294,7 +294,7 @@ uint16_t ui16_PWM_cycles_counter_a = 3;
 uint8_t ui8_pwm_counter_valid_b = 0;
 uint16_t ui16_PWM_cycles_counter_b = 3;
 uint16_t ui16_PWM_cycles_counter_6 = 3;
-uint16_t ui16_PWM_cycles_counter_total = 0xffff;
+uint16_t ui16_PWM_cycles_counter_total = PWM_CYCLES_COUNTER_MAX;
 uint8_t ui8_motor_commutation_type = BLOCK_COMMUTATION;
 volatile uint16_t ui16_motor_speed_erps = 0;
 static uint8_t ui8_motor_rotor_absolute_angle;
@@ -539,7 +539,7 @@ void TIM1_CAP_COM_IRQHandler(void) __interrupt(TIM1_CAP_COM_IRQHANDLER)
  ui16_PWM_cycles_counter_6 = 2;
  ui8_pwm_counter_valid_a = 0;
  ui8_pwm_counter_valid_b = 0;
- ui16_PWM_cycles_counter_total = 0xffff;
+ ui16_PWM_cycles_counter_total = PWM_CYCLES_COUNTER_MAX;
  ui8_g_foc_angle = 0;
  ui8_motor_commutation_type = BLOCK_COMMUTATION;
  ui8_hall_sensors_state_last = 0; // this way we force execution of hall sensors code next time

diff --git a/src/controller/pwm.c b/src/controller/pwm.c
@@ -39,7 +39,7 @@ void pwm_init_bipolar_4q(void) {
  TIM1_TimeBaseInit(0, // TIM1_Prescaler = 0
  TIM1_COUNTERMODE_CENTERALIGNED3,
  // clock = 16MHz; counter period = 840; PWM freq = 16MHz / 840 = 19,047kHz;
- 420, // PWM center aligned mode: counts from 0 to 420 and then down from 420 to 0
+ PWM_PERIOD, // PWM center aligned mode: counts from 0 to PWM_PERIOD and then down from PWM_PERIOD to 0
  1);// will fire the TIM1_IT_UPDATE at every PWM period cycle
 
 //#define DISABLE_PWM_CHANNELS_1_3