CN-112848798-B - Control system and control method for reducing vibration of drive shaft of eco-friendly vehicle

CN112848798BCN 112848798 BCN112848798 BCN 112848798BCN-112848798-B

Abstract

The present disclosure relates to a control system for reducing drive shaft vibrations of an eco-friendly vehicle. The control system includes a drive shaft speed extraction unit that extracts an actual speed of a drive shaft of a motor and extracts a drive shaft speed from which a forced vibration component transmitted to the drive shaft by an engine is removed, a model speed calculation unit that calculates a model speed of the drive shaft, a free vibration calculation unit that calculates a free vibration component based on a deviation between the drive shaft speed and the calculated model speed, and a first torque compensation unit that calculates a free vibration reduction compensation torque for reducing the drive shaft vibration from the free vibration component.

Inventors

GAO YONGKUAN
An Junmo
LIANG BINGXUN
Jiang Hengshi

Assignees

现代自动车株式会社
起亚自动车株式会社

Dates

Publication Date: 20260505
Application Date: 20200821
Priority Date: 20191128

Claims (10)

1. A control system for reducing drive shaft vibrations of an eco-friendly vehicle, comprising: A drive shaft speed extraction unit that extracts an actual speed of a drive shaft of the drive motor and extracts a drive shaft speed from which a forced vibration component transmitted to the drive shaft by the engine is removed; a model speed calculation unit that calculates a model speed of the drive shaft; A free vibration calculating unit calculating a free vibration component based on a deviation between the drive shaft speed and the calculated model speed, and A first torque calculation unit that calculates a free vibration reduction compensation torque for reducing vibration of the drive shaft from the free vibration component, Wherein, the The drive shaft speed extraction unit extracts the drive shaft speed from which the forced vibration component is removed based on a forced vibration frequency that is derived based on a speed of an engine shaft.
2. The control system of claim 1, wherein, The forced vibration frequency is a vibration frequency of the engine, the forced vibration frequency being calculated based on the number of cylinders of the engine and the number of revolutions of the engine.
3. The control system of claim 1, wherein, The drive shaft speed extraction unit includes: A filtering unit extracting the forced vibration component from an actual speed of the drive shaft based on the forced vibration frequency; an amplitude compensation unit for compensating the amplitude of the forced vibration component, and And a forced vibration removal unit that calculates the drive shaft speed, which is a value obtained by subtracting the forced vibration component compensating the amplitude from the actual speed of the drive shaft.
4. The control system of claim 3, wherein, The filtering unit is configured with a combination of a low-pass filter and a high-pass filter that set the forced vibration frequency as a cut-off frequency.
5. The control system of claim 4, wherein, The low-pass filter and the high-pass filter are designed not to change the phase of the actual speed of the drive shaft.
6. The control system of claim 1, wherein, The model speed calculation unit includes: A drive shaft output required torque calculation unit that calculates a drive shaft output required torque based on a torque transmitted to the drive shaft; A drive shaft input torque estimation unit that estimates a drive shaft input torque input to the drive shaft using an actual speed of the drive shaft; A disturbance torque calculation unit that estimates a disturbance torque using the drive shaft output request torque and the drive shaft input torque, and A speed calculation unit that calculates a drive shaft model input torque, in which the disturbance torque is added to the drive shaft output required torque, using the estimated disturbance torque, and calculates a model speed using a drive shaft model in which the drive shaft input torque is set as an input.
7. The control system of claim 1, wherein, The model speed refers to an ideal drive shaft speed excluding the free vibration component, and The value obtained by subtracting the model speed from the drive shaft speed means that the free vibration component of the forced vibration component is removed.
8. A control method for reducing drive shaft vibrations of an eco-friendly vehicle, comprising: extracting an actual speed of a drive shaft of the drive motor; removing a forced vibration component transmitted to the drive shaft by the engine from an actual speed of the drive shaft; calculating a model speed of the drive shaft; Calculating a free vibration component based on a deviation between the drive shaft speed from which the forced vibration component is removed and the calculated model speed, and Calculating a free vibration reduction compensation torque for reducing vibration of the drive shaft from the free vibration component, Wherein, the Removing the forced vibration component from the actual speed of the drive shaft includes: the actual speed of the drive shaft is filtered based on a forced vibration frequency derived based on the speed of the engine shaft to extract the drive shaft speed from which the forced vibration component is removed.
9. The control method according to claim 8, wherein, Removing the forced vibration component from the actual speed of the drive shaft includes: Setting the forced vibration frequency to a cutoff frequency, and extracting the forced vibration component from an actual speed of the drive shaft; compensating the amplitude of the forced vibration component, and The drive shaft speed is calculated, which is a value obtained by subtracting the forced vibration component compensating the amplitude from the actual speed of the drive shaft.
10. The control method according to claim 8, wherein, The model speed refers to an ideal drive shaft speed excluding the free vibration component, and The value obtained by subtracting the model speed from the drive shaft speed is the free vibration component from which the forced vibration component is removed.

Description

Control system and control method for reducing vibration of drive shaft of eco-friendly vehicle Technical Field The present disclosure relates to a control system and a control method for reducing drive shaft vibrations of an eco-friendly vehicle. More particularly, the present disclosure relates to a control system and control method for reducing vibration of a drive shaft of an eco-friendly vehicle using a motor mechanically connected to the drive shaft while reducing free vibration generated in the drive shaft and forced vibration generated by an engine. Background Environmentally friendly vehicles such as Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) travel using an electric motor as a driving source. The electric vehicle travels using only the power of the electric motor that operates based on the battery power. The hybrid vehicle travels by effectively combining the power of the engine and the power of the electric motor. On the other hand, the above-described eco-friendly vehicle has a disadvantage in that the mechanical damping effect possessed by the conventional torque converter cannot be obtained. Therefore, when the driver shifts gears or jerks the accelerator/Jerk (tip-in/out, operation of depressing the accelerator pedal or releasing the accelerator pedal), vibration is generated in the drive shaft, and vibration phenomena such as vibration and Jerk (sudden motion occurring instantaneously) occur. In other words, since the damping means existing between each torque source (torque sorce) (engine and motor) and the drive system is eliminated or small, there is a problem in that vibration from the torque source or vibration from the outside cannot be well damped. In order to reduce such vibration generated in the drive shaft, it is necessary to extract a vibration component of the drive shaft. Since vibration damping performance varies depending on the accuracy of extraction of vibration components, it is important to extract accurate vibration components. Factors that affect the drive shaft are largely divided into free vibration caused by rotation of the drive shaft and forced vibration transmitted from the engine to the motor. Although there are controls to reduce the free vibration and the forced vibration, respectively, the controls to reduce the free vibration and the forced vibration, respectively, cause a problem of mutual interference. In particular, the torque derived to reduce the free vibration has an influence on the torque derived to reduce the forced vibration. Thus, there arises a problem that the overall control performance for reducing vibration is weakened. Disclosure of Invention An object of the present disclosure is to provide a control system and a control method for reducing driving shaft vibration of an eco-friendly vehicle, which can prevent interference from occurring between free vibration compensation torque for reducing free vibration and forced vibration compensation torque for reducing forced vibration. According to one aspect of the present disclosure, a control system for reducing drive shaft vibrations of an eco-friendly vehicle is provided. A control system for reducing drive shaft vibration of an eco-friendly vehicle includes a drive shaft speed extraction unit that extracts an actual speed of a drive shaft of a motor and extracts a drive shaft speed from which a forced vibration component transmitted to the drive shaft by an engine is removed, a model speed calculation unit that calculates a model speed of the drive shaft, a free vibration calculation unit that calculates a free vibration component based on a deviation between the drive shaft speed and the calculated model speed, and a first torque calculation unit that calculates a free vibration reduction compensation torque for reducing drive shaft vibration from the free vibration component. According to an aspect of the present disclosure, in the control system, the drive shaft speed extraction unit may extract the drive shaft speed from which the forced vibration component is removed based on a forced vibration frequency, which is derived based on the speed of the engine shaft. According to an aspect of the present disclosure, in the control system, the forced vibration frequency may be a vibration frequency of the engine, the vibration frequency of the engine being calculated based on a number of cylinders of the engine and a number of revolutions of the engine. According to an aspect of the present disclosure, in the control system, the driving shaft speed extracting unit may include a filtering unit extracting a forced vibration component from an actual speed of the driving shaft based on the forced vibration frequency, an amplitude compensating unit compensating for an amplitude of the forced vibration component, and a forced vibration removing unit calculating a driving shaft speed, which is a value obtained by subtracting the forced vibration component of the compensated amplitude fr