[参考译文] LAUNCHXL-F28379D：双轴驱动器设置扭矩限制和速度恢复延迟

你好、AK、

专家在周一之前不在办公室、请在周一之前等待回复。

此致、

奥普斯

好的。

目前、我正在添加扭矩限制功能、如下所示：

在速度环路内、就在速度 PID 之前、我检查扭矩限制。

函数 torqueLimitCheck()执行以下操作：

float32_t getTorqueLimit(MOTOR_Vars_t *pMotor)
{
    float32_t torqueLimit = 0.0f;
    const float32_t torque2 = 6.0f;
    const float32_t speed2 = 10000.0f;
    const float32_t torque1 = 9.0f;
    const float32_t speed1 = 2000.0f;
    /*
     * Calculate slope
     * Calculate the slope based on two known data points.
     * Data point 1: At 2000 RPM, Max Torque can be 9 Nm
     * Data point 2: At 10000 RPM, Max torque ca be 6 Nm
     * Slope = (Torque2 - Torque1)/(RPM2 - RPM1)
     * Slope = (6 - 9)/(10000 - 2000) = -0.000375
     *
     * Ex If speed is 5000 RPM, What will be the torqueLimit?
     * Torque5000 = Torque1 + Slope*(RPM5000 - RPM1)
     * Torque5000 = 9 + (-0.000375*(5000 - 2000));
     */
    const float32_t slope = -0.000375f;
    torqueLimit = torque1 + (slope *(abs(pMotor->speed.SpeedRpm) - speed1));
    return torqueLimit;
}

void torqueLimitCheck(MOTOR_Vars_t *pMotor)
{

#if(DYNAMIC_TORQUE_LIMIT)
    /*
     * Dynamic torque limit.
     * Dynamic torque limit to achieve maximum possible acceleration, without breaching the OCP limit of the HW.
     * At the Moment with a fixed torque limit set point, the acceleration will depend on the load.
     * At the same fixed torque limit setpoint, No-load will have lower acceleration and
     * as the load is given the acceleration will change.
     * This is verified on the oscilloscope seeing the maximum amplitude of the motor phase current during Motor acceleration.
     */
    float32_t torqueLimitHigh = getTorqueLimit(pMotor);
    float32_t torqueLimitLow = -1.0f * torqueLimitHigh;
#else
    /*
     * Fixed Torque Limit
     */
    float32_t torqueLimitHigh = SPEED_LOOP_TORQUE_LIMIT;
    float32_t torqueLimitLow = -1.0f * torqueLimitHigh;
#endif
    float32_t reductionFactor = 0.0f;

    ***(pMotor);       //Calculate the torque from the Current(pi_iq.ref) and Motor constant Kt.
    if(pMotor->speedRef > 0)    //Clockwise Rotation
    {
        if (pMotor->TorqueNmRef > torqueLimitHigh)
        {
            //Calculate the torque reduction factor
            reductionFactor = __divf32(torqueLimitHigh, pMotor->TorqueNmRef);

            //Reduce the speed reference to maintain limited torque.
            pMotor->rc.SetpointValue *= reductionFactor;
        }
    }
    if(pMotor->speedRef < 0)    //Anti-Clockwise Rotation
    {
        if (pMotor->TorqueNmRef < torqueLimitLow)
        {
            //Calculate the torque reduction factor
            reductionFactor = __divf32(torqueLimitLow, pMotor->TorqueNmRef);

            //Reduce the speed reference to maintain limited torque.
            pMotor->rc.SetpointValue *= reductionFactor;
        }
    }
}

能否验证这是否是在速度环路内实施扭矩限制的正确方法。

谢谢！

你好、

可以。 从理论上讲、可以通过将 限制设置 为 IQ_ref 来设置转矩限值。 您是否有机会尝试一下这个实现方案？ 性能是否符合您的预期？

谢谢。

嘉兴市

尊敬的嘉兴：

是的、我尝试通过限制电流(IQ_ref)来实现扭矩限制。 它确实工作得很好。

我目前所做的一件事是、如果我将 IQ_ref 设置为以 pu 为单位的值、扭矩会受到限制、但我如何将其转换为以 Nm 为单位的实际扭矩？

你能给我任何保证吗?

谢谢！