An active noise cancellation system

Abstract

The present invention relates to a system (1) for actively cancelling the noise originating from the electric drive motors of electric vehicles.

Description

[0001] DESCRIPTION

[0002] AN ACTIVE NOISE CANCELLATION SYSTEM

[0003] Technical Field

[0004] The present invention relates to a system for actively cancelling the noise originating from the electric drive motors of electric vehicles.

[0005] Background of the Invention

[0006] Electric drive motors are used for the movement of electric vehicles. Electric drive motors generate noise with their operation, and the said noise can adversely affect driving comfort. Conventional passive noise reduction methods are used to cancel the said noise. However, existing noise cancellation systems are inadequate for high frequency noise. For this reason, today, there is a need for solutions that actively cancel the noise by generating sound waves in the opposite phase to cancel the noise by detecting the noise frequency of the electric drive motor.

[0007] The international patent document no. WO2013118421A1, an application included in the state of the art, discloses a system configured to reduce the noise coming from the motor. The invention reduces comparative low-frequency noise signals originating from a motor in a hybrid vehicle or an electric vehicle. A vibration detection sensor is placed in a position close to the periphery of the motor and, in addition to detecting the vibrations of the motor, it also detects vibrations at locations slightly distant from the motor. Two detection signals are supplied to a least mean squares (LMS) adaptive filter, the phase of the output signal from the LMS adaptive filter is reversed relative to a vibration detection signal for the motor, and the output signal is supplied to an actuator positioned concentrically to the motor. The actuator is operated so as to attenuate vibrations from the motor. In order to solve the problems mentioned in the invention and to achieve the objects of theinvention, the noise removing device comprises a vibrating body, a sensor in the vicinity of this body to detect vibrations or noises, an actuator in the vicinity of the intermediate element, and an adaptive fdter that drives the actuator by multiplying the sensor signal by a certain coefficient. The actuator reduces noise by operating in the opposite phase to the sensor signal. In a preferred embodiment, a second sensor detects vibrations or noise distant from the vibrating body. The adaptive filter uses a specific algorithm to obtain a coefficient from the signal of the second sensor, and this coefficient is then used to drive the actuator. The coefficient is adjusted to minimize the signal of the second sensor. The adaptive filter is a least mean squares filter, and the sensor consists of a film-shaped polymer piezoelectric element.

[0008] Summary of the Invention

[0009] An object of the present invention is to realize a system which enables the generation of sound waves in the opposite phase to the recorded noise frequencies by using, during active driving, the noise data generated by the electric drive motors used in electric vehicles and recorded during the test phase.

[0010] Detailed Description of the Invention

[0011] “An Active Noise Cancellation System” realized to fulfil the objective of the present invention is shown in the figure attached, in which:

[0012] Figure 1 is a schematic view of the inventive system.

[0013] The components illustrated in the figure are individually numbered, where the numbers refer to the following:

[0014] 1. System

[0015] 2. Electric motor3. Actuator

[0016] 4. Control unit

[0017] An inventive system (1) for actively reducing the noise originating from the electric drive motors of electric vehicles comprises

[0018] at least one electric motor (2);

[0019] at least one actuator (3) which is configured to generate a sound wave in the opposite phase in order to reduce the noise generated by the operation of the electric motor (2); and

[0020] at least one control unit (4) which is configured to establish communication with the electric motor (2) and the actuator (3); to exchange data through this established communication; to keep a record of noise data predetermined according to the operating state of the electric motor (2) in the form of speed and load data and sound wave data to be used to reduce noise, matched with noise data; to be triggered by the movement of the vehicle and to actively receive the operating status data of the electric motor (2) through the communication established with the electric motor (2); to access the recorded data depending on the operating status data; and to enable sound waves in the opposite phase to be generated by triggering the actuator (3) according to the sound wave data required to be generated in the said noise.

[0021] The electric motor (2) included in the inventive system (1) is used in electric vehicles and is configured to enable the noise frequencies generated by the motor during the test phase to be recorded in the control unit (4) by means of a sensor. The electric motor (2) is configured to share real-time data in the form of speed and load with the control unit (4) after starting operation.

[0022] The actuator (3) included in the inventive system (1) is a piezoelectric element and is configured to be in communication with the control unit (4) and to generate opposite phase sound waves through this established communication. Thepiezoelectric elements used as the actuator (3) are configured to respond quickly and generate sound waves in a wide frequency range. In this way, the control unit (4) enables the high frequency noise generated by the electric motor (2) to be reduced by triggering the actuators (3). In the preferred embodiment of the invention, the actuators (3) are configured to be placed at the points in the vehicle where the noise of the electric motor (2) is most noticeable and to provide more effective noise cancellation in the targeted area.

[0023] The control unit (4) included in the inventive system (1) is configured to be in communication with the electric motor (2) and the actuator (4) through any communication protocol included in the state of art and to exchange data through the established communication. The control unit (4) is configured to trigger the actuator (3) to generate a sound wave in the opposite direction depending on the noise frequency recorded in the operating status data received from the electric motor (2). The control unit (4) is configured for narrowband cancellation and to target only the required frequencies in order to cancel the noise generated by the electric motor (2). In this way, less energy is consumed. The control unit (4) is preferably an electric motor (2) control processor and is configured to keep a record of the noise data generated by the motor depending on its operating status and the frequency of the sound wave to be generated according to the noise data. In the preferred embodiment of the invention, the control unit (4) is configured to operate in integration with the electric motor (2) and to dynamically adjust the actuators (3) depending on the operating status of the electric motor. In this way, it is enabled to monitor the noise sources in the electric motor (2) more effectively and to cancel the noise.

[0024] The control unit (4) included in the inventive system (1) is configured to use adaptive and dynamic algorithms and to adjust itself depending on motor speed, operating conditions and environmental changes. The control unit (4) is configured to use adaptive algorithms in the form of LMS (least mean squares) and RLS (Recursive Least Squares) and to optimize its performance.The inventive active noise cancellation system (1) enables the noise generated by the electric motor (2) to be reduced by means of sound waves in the opposite direction generated by the actuators (3). For this, it records the sound waves in the opposite phase matched with the noise data generated by the electric motor (2) during the test phase. In this way, depending on the speed and load of the electric motor, sound waves are generated in the opposite direction in accordance with the predetermined noise data. The system (1) is more efficient and effective than conventional noise cancellation methods. In this way, it effectively reduces the noise generated by driving the electric motors of electric vehicles and increases driving comfort.

[0025] Within these basic concepts; it is possible to develop various embodiments of the inventive “An Active Noise Cancellation System (1)”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

Claims

CLAIMS1. A system (1) for actively reducing the noise originating from the electric drive motors of electric vehicles; characterized byat least one electric motor (2);at least one actuator (3) which is configured to generate a sound wave in the opposite phase in order to reduce the noise generated by the operation of the electric motor (2); andat least one control unit (4) which is configured to establish communication with the electric motor (2) and the actuator (3); to exchange data through this established communication; to keep a record of noise data predetermined according to the operating state of the electric motor (2) in the form of speed and load data and sound wave data to be used to reduce noise, matched with noise data; to be triggered by the movement of the vehicle and to actively receive the operating status data of the electric motor (2) through the communication established with the electric motor (2); to access the recorded data depending on the operating status data; and to enable sound waves in the opposite phase to be generated by triggering the actuator (3) according to the sound wave data required to be generated in the said noise.

2. A system (1) according to Claim 1 ; characterized by the electric motor (2) which is used in electric vehicles and is configured to enable the noise frequencies generated by the motor during the test phase to be recorded in the control unit (4) by means of a sensor.

3. A system (1) according to Claim 1 or 2; characterized by the electric motor (2) which is configured to share real-time data in the form of speed and load with the control unit (4) after starting operation.

4. A system (1) according to any one of the preceding claims; characterized by the actuator (3) which is a piezoelectric element and is configured to be in communication with the control unit (4) and to generate opposite phase sound waves through this established communication.

5. A system (1) according to Claim 4; characterized by the piezoelectric elements which are used as the actuator (3) and are configured to respond quickly and generate sound waves in a wide frequency range.

6. A system (1) according to any one of the preceding claims; characterized by the actuators (3) which are configured to be placed at the points in the vehicle where the noise of the electric motor (2) is most noticeable and to provide more effective noise cancellation in the targeted area.

7. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is configured to be in communication with the electric motor (2) and the actuator (4) through any communication protocol included in the state of art and to exchange data through the established communication.

8. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is configured to trigger the actuator (3) to generate a sound wave in the opposite direction depending on the noise frequency recorded in the operating status data received from the electric motor (2).

9. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is configured for narrowband cancellation and to target only the required frequencies in order to cancel the noise generated by the electric motor (2).

10. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is an electric motor (2) control processor and is configuredto decide the frequency of the sound wave to be generated according to the noise data and the noise data generated by the motor depending on its operating status.

11. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is configured to operate in integration with the electric motor (2) and to dynamically adjust the actuators (3) depending on the operating status of the electric motor.

12. A system (1) according to any one of the preceding claims; characterized by the control unit (4) which is configured to use adaptive and dynamic algorithms and to adjust itself depending on motor speed, operating conditions and environmental changes.

13. A system (1) according to Claim 12; characterized by the control unit (4) which is configured to use adaptive algorithms in the form of LMS (least mean squares) and RLS (Recursive Least Squares) and to optimize its performance.

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