A dual-shaft motor and control method for an electric power steering system of an automobile

Abstract

The application discloses a double-shaft motor and a control method of an automobile electric power steering system, which comprises a shell, a high-voltage winding, a low-voltage winding, a monitoring unit and a low-voltage controller. The shell is internally configured as a first accommodating space and a second accommodating space, and the first accommodating space and the second accommodating space are not communicated. The high-voltage winding is accommodated in the first accommodating space and is used for providing steering assistance when a vehicle is normally driven. The monitoring unit is connected with the high-voltage winding and is used for monitoring the rotating speed of the high-voltage winding. The low-voltage winding is accommodated in the second accommodating space, the low-voltage winding is connected with the monitoring unit, the monitoring unit is used for monitoring the rotating speed of the low-voltage winding, and the monitoring unit is connected with the low-voltage controller. In the application, the high-voltage winding and the low-voltage winding are designed separately, the influence of the high-voltage winding damage on the low-voltage winding is avoided, no power is fed to the low-voltage winding when the high-voltage winding is operated, and the high-low voltage switching response time is effectively shortened.

Description

Technical Field

[0001] This invention relates to the field of automotive equipment technology, and in particular to a dual-axis motor and control method for an automotive electric power steering system. Background Technology

[0002] As new energy electric vehicles continue to develop, higher requirements are being placed on the safety and reliability of the entire vehicle.

[0003] Currently, a dual-source motor for steering systems in new energy vehicles is available on the market. Its principle involves a single motor stator with two sets of windings: a high-voltage winding and a low-voltage winding. The high-voltage winding is connected to the vehicle's power battery, and the low-voltage winding is connected to the low-voltage battery. When the vehicle's high-voltage system malfunctions and cannot provide power steering, the low-voltage power supply is activated to provide short-term emergency power steering. However, this dual-source motor has the following problems during use:

[0004] 1) When the high-voltage winding burns out, the low-voltage winding will also burn out, resulting in no emergency power steering.

[0005] 2) When the high voltage is working, the low voltage will continuously supply power to the vehicle's low voltage battery, causing the vehicle's low voltage to be too high alarm.

[0006] 3) The response time for switching to low voltage after a high voltage failure is too slow. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a dual-axis motor for an automotive electric power steering system.

[0008] This invention provides a dual-axis motor for an automotive electric power steering system, comprising a housing, a high-voltage winding, a low-voltage winding, a monitoring unit, and a low-voltage controller;

[0009] The housing is configured with a first accommodating space and a second accommodating space, which are not connected to each other;

[0010] The high-voltage winding is housed within the first accommodating space and is used to provide steering assistance when the vehicle is driving normally. The monitoring unit is connected to the high-voltage winding and is used to monitor the rotational speed of the high-voltage winding.

[0011] The low-voltage winding is housed within the second accommodating space. The low-voltage winding is connected to the monitoring unit, which is used to monitor the rotational speed of the low-voltage winding. The monitoring unit is also connected to the low-voltage controller.

[0012] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0013] The monitoring unit includes a first sensor and a second sensor. The first sensor is disposed in the first accommodating space and is electrically connected to the high-voltage winding; the second sensor is disposed in the second accommodating space and is electrically connected to the low-voltage winding.

[0014] The first sensor and the second sensor are respectively connected to the low-voltage controller for communication.

[0015] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0016] Both the first sensor and the second sensor include position sensors.

[0017] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0018] The high-voltage winding includes a first rotor assembly and a first stator assembly. The first rotor assembly is rotatably connected to the housing, and the first stator assembly is arranged around the first rotor assembly.

[0019] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0020] The low-voltage winding includes a second rotor assembly and a second stator assembly, the second rotor assembly being rotatably connected to the housing, and the second stator assembly being arranged around the second rotor assembly.

[0021] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0022] The housing includes an upper housing and a lower housing, wherein the upper housing and the lower housing are detachably connected, the upper housing is internally configured with at least one placement space, the low-voltage controller is located in the at least one placement space, and the first accommodating space and the second accommodating space are arranged side by side in the lower housing.

[0023] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0024] The lower housing has a first front end cover and a second front end cover on its first side, and a first rear end cover and a second rear end cover on its second side. The first side and the second side are arranged opposite to each other. The first front end cover and the first rear end cover are respectively fastened to both ends of the first rotor assembly. The second front end cover and the second rear end cover are respectively fastened to both ends of the second rotor assembly.

[0025] The dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0026] The upper housing is equipped with multiple data plugs.

[0027] This invention also provides a control method for a dual-axis motor in an automotive electric power steering system, applied to a low-voltage controller of the dual-axis motor in an automotive electric power steering system, characterized in that...

[0028] Obtain the first rotational speed of the high-voltage winding;

[0029] Determine whether the first rotational speed is lower than a preset threshold;

[0030] If the first rotational speed is lower than a preset threshold, the second rotational speed of the low-voltage winding is increased to the first preset rotational speed.

[0031] The control method for the dual-axis motor in the aforementioned automotive electric power steering system may also have the following characteristics:

[0032] If the first rotational speed is higher than the preset threshold, the second rotational speed of the low-voltage winding is maintained at the second preset rotational speed.

[0033] The dual-axis motor of the automotive electric power steering system of the present invention houses the high-voltage winding in a first accommodating space and the low-voltage winding in a second accommodating space, both within the same housing. This separate design of the high-voltage and low-voltage windings within a single housing effectively prevents damage to the high-voltage winding from affecting the low-voltage winding. In the event of a malfunction in the high-voltage winding, the low-voltage winding intervenes to provide short-term emergency power steering, ensuring steering continuity and improving steering safety. Simultaneously, it effectively ensures that no back electromotive force is generated between the high-voltage and low-voltage windings during normal vehicle operation, improving vehicle stability.

[0034] Other features and advantages of the invention will become clear when reading the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0036] Figure 1 This is a three-dimensional schematic diagram of a dual-axis motor in an automotive electric power steering system according to one embodiment;

[0037] Figure 2This is a front view of a dual-axis motor in an automotive electric power steering system according to one embodiment;

[0038] Figure 3 This is a vertical sectional view of a dual-axis motor in an automotive electric power steering system according to one embodiment;

[0039] Figure 4 This is a transverse sectional view of a dual-axis motor of an automotive electric power steering system according to one embodiment;

[0040] Figure 5 This is a block diagram of a control method for a dual-axis motor in an automotive electric power steering system, as described in this embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0042] In order to prevent damage to the high-voltage winding from affecting the low-voltage winding during the operation of a dual-axis motor, and to prevent the high-voltage winding from generating a back electromotive force on the low-voltage winding side during normal vehicle operation, the present invention designs the high-voltage winding and the low-voltage winding separately and integrates them in the same housing. This effectively improves the stability of the dual-axis motor operation and ensures the continuity and safety of steering.

[0043] The following detailed description, with reference to the accompanying drawings, describes the dual-axis motor of the automotive electric power steering system provided in this disclosure.

[0044] Figure 1 A perspective schematic diagram of a specific embodiment of a dual-axis motor in an automotive electric power steering system of the present disclosure is shown. Figure 2 A front view of the dual-axis motor of the automotive electric power steering system of this disclosure is shown. Figure 3 This diagram shows a vertical cross-sectional view of a dual-axis motor in an automotive electric power steering system. Figure 4 A cross-sectional schematic diagram of a dual-axis motor in an automotive electric power steering system is shown.

[0045] Combination Figures 1 to 4 As shown, the dual-axis motor of the automotive electric power steering system includes a housing 1, a high-voltage winding 2, a low-voltage winding 3, a monitoring unit 4, and a low-voltage controller 5.

[0046] According to one embodiment of this disclosure, referring to Figures 1 to 4 As shown, the housing 1, serving as the main load-bearing structure of the dual-axis motor, is internally configured with a first accommodating space 11 and a second accommodating space 12. The first accommodating space 11 and the second accommodating space 12 are not connected; that is, through the design of the first accommodating space 11 and the second accommodating space 12, the main operating components of the motor can be housed within these spaces. For example, the high-voltage winding 2 can be housed in the first accommodating space 11, and the low-voltage winding 3 can be housed in the second accommodating space 12. Alternatively, the low-voltage winding 3 can be housed in the first accommodating space 11, and the high-voltage winding 2 can be housed in the second accommodating space 12.

[0047] In this specific embodiment, the high-voltage winding 2 is disposed in the first accommodating space 11 and the low-voltage winding 3 is disposed in the second accommodating space 12 as an example for illustration.

[0048] For example, refer to Figure 1 and Figure 4 As shown, the high-voltage winding 2 is the main winding, used to provide steering assistance during normal vehicle operation, and is housed within the first accommodating space 11. The high-voltage winding 2 includes a first rotor assembly 21 and a first stator assembly 22. The first rotor assembly 21 is rotatably connected to the housing 1, and the first stator assembly 22 is arranged around the first rotor assembly 21. It should be noted that both the first stator assembly 21 and the first rotor assembly 22 can utilize existing technology to achieve the high-voltage winding providing steering assistance during normal vehicle operation; the specific structures of the first rotor assembly 21 and the first stator assembly 22 will not be described in detail here.

[0049] For example, refer to Figures 1 to 4 As shown, the low-voltage winding 3 is housed within the second accommodating space 12. When the vehicle is in normal operation, the low-voltage winding 3 operates with low power output. When the high-voltage winding 2 malfunctions, the low-voltage winding 3 intervenes and provides short-term emergency power steering to guide the disabled vehicle to a safe location, effectively ensuring the safety of the driver.

[0050] Specifically, the low-voltage winding 3 includes a second rotor assembly 31 and a second stator assembly 32. The second rotor assembly 31 is rotatably connected to the housing 1, and the second stator assembly 32 is arranged around the second rotor assembly 31. It should be noted that both the second stator assembly 32 and the second rotor assembly 31 can be implemented using existing technology, enabling the low-voltage winding 3 to provide short-term emergency power steering for the vehicle. The specific structures of the second stator assembly 32 and the second rotor assembly 31 will not be described in detail here.

[0051] For example, refer to Figure 1As shown, the monitoring unit 4 is located inside the housing 1 and is used to monitor the operating status of the high-voltage winding 2 and the low-voltage winding 3 in real time. Specifically, the monitoring unit 4 includes a first sensor 41 and a second sensor 42. The first sensor 41 is located in the first accommodating space 11 and is electrically connected to the high-voltage winding 2. Specifically, it monitors the operating status of the first rotor assembly 21 in the high-voltage winding 2 in real time. The second sensor 42 is located in the second accommodating space 12 and is electrically connected to the low-voltage winding 3. It monitors the operating status of the low-voltage winding 3 in real time. The first sensor 41 and the second sensor 42 are respectively communicatively connected to the low-voltage controller 5.

[0052] Both the first sensor 41 and the second sensor 42 can be position sensors. The position sensor 41, which is connected to the high-voltage winding 2, is used to collect the rotational speed of the first rotor assembly 21 in real time. The position sensor 42, which is connected to the low-voltage winding 3, is used to monitor the operating status of the low-voltage winding 3 in real time. For example, it can collect the rotational speed, magnetic pole position, or output power of the second rotor assembly 31 in real time.

[0053] For example, refer to Figure 3 As shown, the low-voltage controller 5 is installed in the housing 1 and is electrically connected to the monitoring unit 4 to switch the high-voltage winding 2 to the low-voltage winding 3 when the high-voltage winding 2 is malfunctioning. The low-voltage controller 5 can be used to collect real-time information on the rotational speed of the high-voltage winding 2 and fault information of the high-voltage winding 2 from the first sensor 41.

[0054] For example, when the vehicle is driving normally and the high-voltage winding 2 system is intact, the high-voltage winding 2 in the dual-source motor continuously outputs power to provide steering assistance. The first sensor 41 collects the rotational speed of the first rotor assembly 21 of the high-voltage winding 2 in real time and converts this speed into a steering signal, which is then transmitted to the low-voltage controller 5. When the high-voltage winding 2 malfunctions, the rotational speed of the first rotor assembly 21 decreases. The first sensor 41 detects the rotational speed signal of the first rotor assembly 21 and transmits it to the low-voltage controller 5. When the rotational speed of the first rotor assembly 21 drops to a set value, for example, from 1500 RPM (Revolutions Per Minute) to 800 RPM, the low-voltage controller 5 switches the high-voltage winding 2 to the low-voltage winding 3 and increases the output power of the second rotor assembly 31 to its peak state to provide short-term emergency steering assistance.

[0055] It should be noted that the operating status of the high-voltage winding 2 and the low-voltage winding 3 is monitored in real time by the first sensor 41 and the second sensor 42, and the rapid switching between the high-voltage winding 2 and the low-voltage winding 3 is completed by the low-voltage controller 5, thereby greatly reducing the emergency response switching time. Specifically, the first sensor 41 and the second sensor 42 can be connected to a host computer (e.g., a host computer or chip used to control vehicle operation). The time from the shutdown of the first rotor assembly 21 in the high-voltage winding 2 to the time when the speed of the second rotor assembly 31 in the low-voltage winding 3 reaches the speed required for short-term emergency assistance is the emergency response switching time. In this specific embodiment, the emergency response switching time is less than 500ms.

[0056] For example, refer to Figure 1 and Figure 2 As shown in the specific embodiment of this disclosure, the housing 1 includes an upper housing 13 and a lower housing 14, wherein the upper housing 13 and the lower housing 14 are detachably connected to facilitate the assembly and disassembly of the housing, as well as the repair and maintenance of the dual-source motor. The upper housing 13 is internally configured with at least one placement space 131, and the low-voltage controller 5 is located in one of the placement spaces 131. The first accommodating space 11 and the second accommodating space 12 are arranged side by side in the lower housing 14. By placing the high-voltage winding 2 in the first accommodating space 11, the low-voltage winding 3 in the second accommodating space 12, and the low-voltage controller 5 in one of the placement spaces 131, the high-voltage winding 2 and the low-voltage winding 3 of the dual-source motor are designed separately, avoiding the impact of damage to the high-voltage winding 2 on the low-voltage winding 3, effectively ensuring the continuity of steering and improving steering safety.

[0057] Meanwhile, in a specific embodiment of this disclosure, when the vehicle is driving normally and the high-voltage winding 2 is running, the low-voltage winding 3 operates in a low-power output state, thereby effectively avoiding the generation of back EMF on one side of the low-voltage winding 3 and avoiding feeding power to the low-voltage battery on one side of the low-voltage winding 3.

[0058] For example, refer to Figures 3 to 4 As shown, the first side of the lower housing 14 is provided with a first front end cover 15 and a second front end cover 16, and the second side of the lower housing 14 is provided with a first rear end cover 17 and a second rear end cover 18. The first and second sides are arranged opposite to each other. The first front end cover 15 and the first rear end cover 17 are respectively fastened to both ends of the first rotor assembly 21; the second front end cover 16 and the second rear end cover 18 are respectively fastened to both ends of the second rotor assembly 31. This facilitates the quick installation or removal of the high-voltage winding 2 and the low-voltage winding 3 in the housing 1, and also facilitates maintenance and other work.

[0059] For example, refer to Figures 1 to 2As shown, the upper housing 13 is provided with multiple data plugs 19, which can be used for quick electrical connection to components within the placement space 131. For example, they can be connected to the low-voltage battery required for the low-voltage winding 3, and the high-voltage battery required for the high-voltage winding 2. Alternatively, they can be used for electrical connection to the first sensor 41, the second sensor 42, and the low-voltage controller 5.

[0060] The dual-axis motor of the automotive electric power steering system disclosed herein houses the high-voltage winding 2 within a first accommodating space 11 and the low-voltage winding 3 within a second accommodating space 12. Both the first and second accommodating spaces 11 and 12 are located within the same housing 1. This design, with both the high-voltage winding 2 and the low-voltage winding 3 separately designed within a single housing 1, effectively prevents damage to the high-voltage winding 2 from affecting the low-voltage winding 3. Furthermore, in the event of an malfunction in the high-voltage winding 2, the low-voltage winding 3 intervenes to provide short-term emergency power steering, ensuring steering continuity and improving steering safety. Simultaneously, it effectively ensures that no back electromotive force is generated between the high-voltage winding 2 and the low-voltage winding 3 during normal vehicle operation, thus improving vehicle stability.

[0061] like Figure 5 As shown, this disclosure also provides a control method for a dual-axis motor in an automotive electric power steering system, applied to a low-voltage controller of the dual-axis motor in the automotive electric power steering system. The method includes the following steps:

[0062] S100: Obtain the first rotational speed of the high-voltage winding. The first rotational speed is the rotational speed at which the high-voltage winding outputs its normal power when the vehicle is in normal operation.

[0063] S200: Determine whether the first rotational speed is lower than a preset threshold. The preset threshold can be flexibly set according to different car models or types. For example, in this specific embodiment, the preset threshold can be 30% or less of the first rotational speed.

[0064] If the judgment result is yes, proceed to step S200; if the judgment result is no, proceed to step S400.

[0065] S300: If the first speed is lower than a preset threshold, the second speed of the low-voltage winding is increased to the first preset speed. The second speed of the low-voltage winding is its speed during low-output power operation, which is lower than the first speed of the high-voltage winding. The first preset speed is the peak output power of the motor during normal vehicle operation. When the first speed is lower than the preset threshold, the low-voltage winding intervenes and takes over from the high-voltage winding, increasing the second speed to the peak output power of the motor to provide emergency power steering during vehicle operation.

[0066] S400: If the first rotational speed is higher than a preset threshold, the second rotational speed of the low-voltage winding is maintained at the second preset rotational speed. The second preset rotational speed can be equivalent to the rotational speed of the low-voltage winding when it is operating at low power while the high-voltage winding is running normally. The second preset rotational speed is lower than the first preset rotational speed.

[0067] By implementing the above control methods, the low-voltage controller can effectively improve the rapid switching efficiency between the high-voltage winding and the low-voltage winding of the dual-shaft motor during vehicle operation. When the high-voltage winding fails, the low-voltage winding intervenes and replaces the high-voltage winding, thereby increasing the instantaneous output power of the dual-shaft motor, providing short-term emergency power steering for vehicle operation, ensuring steering continuity, and improving steering safety.

[0068] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A dual-axis motor for an automotive electric power steering system, characterized in that, It includes the housing, high-voltage winding, low-voltage winding, monitoring unit, and low-voltage controller; The housing is configured with a first accommodating space and a second accommodating space, which are not connected to each other; The high-voltage winding is housed within the first accommodating space and is used to provide steering assistance when the vehicle is driving normally. The monitoring unit is connected to the high-voltage winding and is used to monitor the rotational speed of the high-voltage winding. The low-voltage winding is housed within the second accommodating space. The low-voltage winding is connected to the monitoring unit, which is used to monitor the rotational speed of the low-voltage winding. The monitoring unit is also connected to the low-voltage controller. The high-voltage winding includes a first rotor assembly and a first stator assembly, the low-voltage winding includes a second rotor assembly and a second stator assembly, the housing includes an upper housing and a lower housing, a first front end cover and a second front end cover are provided on a first side of the lower housing, and a first rear end cover and a second rear end cover are provided on a second side of the lower housing, wherein the first side and the second side are arranged opposite to each other, the first front end cover and the first rear end cover are respectively fastened to both ends of the first rotor assembly; the second front end cover and the second rear end cover are respectively fastened to both ends of the second rotor assembly.

2. The dual-axis motor for the automotive electric power steering system as described in claim 1, characterized in that, The monitoring unit includes a first sensor and a second sensor. The first sensor is disposed in the first accommodating space and is electrically connected to the high-voltage winding; the second sensor is disposed in the second accommodating space and is electrically connected to the low-voltage winding. The first sensor and the second sensor are respectively connected to the low-voltage controller for communication.

3. The dual-axis motor of the automotive electric power steering system as described in claim 2, characterized in that, Both the first sensor and the second sensor include position sensors.

4. The dual-axis motor for the automotive electric power steering system as described in claim 1, characterized in that, The first rotor assembly is rotatably connected to the housing, and the first stator assembly is arranged around the first rotor assembly.

5. The dual-axis motor of the automotive electric power steering system as described in claim 4, characterized in that, The second rotor assembly is rotatably connected to the housing, and the second stator assembly is arranged around the second rotor assembly.

6. The dual-axis motor for the automotive electric power steering system as described in claim 5, characterized in that, The upper housing and the lower housing are detachably connected. The upper housing has at least one placement space inside, and the low-voltage controller is located in the at least one placement space. The first accommodating space and the second accommodating space are arranged side by side in the lower housing.

7. The dual-axis motor for the automotive electric power steering system as described in claim 6, characterized in that, The upper housing is equipped with multiple data plugs.

8. A control method for a dual-axis motor in an automotive electric power steering system, applied to the low-voltage controller of the dual-axis motor in the automotive electric power steering system as described in claims 1-7, characterized in that, Obtain the first rotational speed of the high-voltage winding; Determine whether the first rotational speed is lower than a preset threshold; If the first rotational speed is lower than a preset threshold, the second rotational speed of the low-voltage winding is increased to the first preset rotational speed.

9. The control method for a dual-axis motor in an automotive electric power steering system according to claim 8, characterized in that, The control method further includes: If the first rotational speed is higher than the preset threshold, the second rotational speed of the low-voltage winding is maintained at the second preset rotational speed.

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