本帖最后由 cry1109 于 2020-2-27 17:23 编辑
STM32F407的TIM1输出PWM,cubeMX配置。使用的是内部时钟,配置系统时钟为64MHz。TIM2每200us进入一次中断,每次中断中增加或减少PWM脉冲频率,达到匀加速、匀减速的效果。但是匀加速期间发出的PWM脉冲个数并不等与计算的个数,而匀减速期间所发的脉冲个数等于计算的个数。
比如说脉冲频率从50Hz增加到28346Hz,期间需要发出502脉冲,可实际至发了6个脉冲;脉冲频率从28346Hz降低到50Hz时,实际发出的脉冲个数504个。从大降到小没问题,从小增到大就不对了,求解。
速度调节函数:void Speed_Adjust(uint16_t delta_speed)
{
if(Motor.ActiveSpeed > (Motor.TargetSpeed+delta_speed))
{
Motor.ActiveSpeed -= delta_speed;
}
else if(Motor.ActiveSpeed < (Motor.TargetSpeed-delta_speed))
{
Motor.ActiveSpeed += delta_speed;
}
else
{
Motor.ActiveSpeed = Motor.TargetSpeed;
}
if(Motor.ActiveSpeed < 50)
{
Motor.ActiveSpeed = 50;
}
else if(Motor.ActiveSpeed > 1000000)
{
Motor.ActiveSpeed = 1000000;
}
__HAL_TIM_SET_AUTORELOAD(&htim1,MOTOR_TIME_FREQ/Motor.ActiveSpeed);
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, (MOTOR_TIME_FREQ/Motor.ActiveSpeed)/2);
}
期望的电机运动轨迹:
友情提示: 此问题已得到解决,问题已经关闭,关闭后问题禁止继续编辑,回答。
- void MX_TIM1_Init(void)
- {
- TIM_ClockConfigTypeDef sClockSourceConfig = {0};
- TIM_MasterConfigTypeDef sMasterConfig = {0};
- TIM_OC_InitTypeDef sConfigOC = {0};
- TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
- htim1.Instance = TIM1;
- htim1.Init.Prescaler = 31;
- htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
- htim1.Init.Period = 40000;
- htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
- htim1.Init.RepetitionCounter = 0;
- htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
- if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
- {
- Error_Handler();
- }
- sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
- if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
- {
- Error_Handler();
- }
- if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
- {
- Error_Handler();
- }
- sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
- sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
- if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
- {
- Error_Handler();
- }
- sConfigOC.OCMode = TIM_OCMODE_PWM1;
- sConfigOC.Pulse = 20000;
- sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
- sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
- sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
- sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
- sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
- if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
- {
- Error_Handler();
- }
- __HAL_TIM_DISABLE_OCxPRELOAD(&htim1, TIM_CHANNEL_1);
- sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
- sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
- sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
- sBreakDeadTimeConfig.DeadTime = 0;
- sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
- sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
- sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
- if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
- {
- Error_Handler();
- }
- HAL_TIM_MspPostInit(&htim1);
- }
复制代码所以我怀疑问题出在定时器的影子寄存器。没有使能的时候,减速阶段的脉冲个数是对的。
一个方向没问题,另一个方向有问题,问题应该好找的
找到问题了。频率从小增到大的过程中,自动重载值是由大变小的,在实时的调节频率时由于禁止了影子寄存器,如果最新设置的自动重载值小于定时器的当前计数值,就会导致当前即将发出的脉冲丢失;如果频率从大减小的过程自动重载值是由小变大的,所以最新设置的自动重载值不会大于定时器的当前计数值,脉冲也就不会丢失。
void Speed_Adjust(uint16_t delta_speed)
{
if(Motor.ActiveSpeed > (Motor.TargetSpeed+delta_speed))
{
Motor.ActiveSpeed -= delta_speed;
}
else if(Motor.ActiveSpeed < (Motor.TargetSpeed-delta_speed))
{
Motor.ActiveSpeed += delta_speed;
}
else
{
Motor.ActiveSpeed = Motor.TargetSpeed;
}
if(Motor.ActiveSpeed < 50)
{
Motor.ActiveSpeed = 50;
}
else if(Motor.ActiveSpeed > 1000000)
{
Motor.ActiveSpeed = 1000000;
}
if((MOTOR_TIME_FREQ/Motor.ActiveSpeed) > (__HAL_TIM_GET_COUNTER(&htim1)))
{
__HAL_TIM_SET_AUTORELOAD(&htim1,MOTOR_TIME_FREQ/Motor.ActiveSpeed);
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, (MOTOR_TIME_FREQ/Motor.ActiveSpeed)/2);
}
}
代码加一句,只有设置的自动重载在大于当前计数值时才更新自动重装值和输出比较值。
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