Method for improving starting performance of inflation pump in air suspension system

Abstract

The invention belongs to the technical field of automobiles, and discloses a method for improving the starting performance of an inflation pump in an air suspension system, which comprises the following steps: S1, replacing a brush direct current motor in the inflation pump with a brushless direct current motor; s2, starting the brushless direct current motor to operate through a motor controller according to the PWM duty ratio within the range of 20%-30%; and S4, according to the rotating speed difference value, calculating a PWM duty ratio needing to be output in the next step by using a PID algorithm, and controlling the brushless direct current motor to operate according to the PWM duty ratio through a motor controller. During starting, the PWM duty ratio modulation function of the brushless direct current motor is used, the voltage provided by the power supply module for the motor end is controlled, the PID control algorithm is combined, the PWM duty ratio is calculated according to the target speed needing to be controlled, the rotating speed is controlled, it is guaranteed that the starting speed rises stably, and therefore the starting current rises stably, and the starting speed is stable. And peak noise is avoided, and starting noise is controlled to be at a low level.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automobile, in particular relates to a method for improving the starting performance of a pump in an air suspension system. BACKGROUND

[0002] With the development of electric vehicles and intelligent vehicles, more and more vehicles are equipped with adjustable air suspension systems to improve the driving experience. The adjustable air suspension can adjust the softness and hardness of the shock absorption and the height of the vehicle body by changing the volume of the gas in the air spring. It can automatically lower the vehicle body height when driving at high speed, thereby reducing wind resistance and improving the handling performance and stability of the vehicle. When driving on a bumpy road, it automatically raises the vehicle body height, thereby improving the passing ability and making the vehicle more comfortable in dealing with road conditions. Compared with low-end vehicles with traditional suspension systems, vehicles with adjustable air suspension systems have better adaptability to road conditions and higher comfort and stability.

[0003] The pump is the core component of the entire air suspension system, which consists of a pump head and a motor. The motor drives the piston inside the pump head to move, compressing the atmospheric gas into high-pressure gas to supply air to the air suspension system. The traditional pump used in air suspension systems uses a brush DC motor. When starting, the brush motor usually uses a control strategy of running as soon as it is powered on. The starting current is very large, which can reach 4-7 times the rated current when the motor is idle, and 8-10 times the rated current or even more when the motor is loaded. A large starting current can cause the voltage of the vehicle to drop, affecting the normal operation of other electrical equipment, and may also cause under-voltage protection, causing the equipment to shut down. At the same time, the large starting current can cause the motor winding to heat up, thereby accelerating the aging of the insulation and affecting the service life of the motor. Therefore, we propose a method for improving the starting performance of the pump in the air suspension system to solve the above problems. SUMMARY

[0004] To solve the above problems, the present application provides a method for improving the starting performance of the pump in the air suspension system, which solves the problems of large starting current, large starting noise and affecting the normal operation of the equipment of the traditional brush DC motor.

[0005] The present application is realized by the following scheme: a method for improving the starting performance of the pump in the air suspension system, comprising the following steps: S1, replacing the brush DC motor in the pump with a brushless DC motor, the brushless DC motor being connected with a motor controller; S2, starting the brushless DC motor to run by the motor controller with a duty cycle in the range of 20%-30% PWM; S3, calculating the difference between the current speed and the target speed of the brushless DC motor after the brushless DC motor runs for a set time. S4. Based on the speed difference, the PWM duty cycle to be output in the next step is calculated using the PID algorithm, and the brushless DC motor is controlled by the motor controller to run according to the PWM duty cycle. S5. Continue executing steps S3 and S4 until the rotational speed reaches the target rotational speed.

[0006] A further improvement of the method for improving the starting performance of an air pump in an air suspension system is that the air pump further includes a piston, the output end of the brushless DC motor is connected to the piston, and is used to drive the piston to reciprocate. The piston has a point of maximum resistance during the reciprocating motion. When the piston is in its initial position near the point of maximum resistance, the method for starting the brushless DC motor in step S2 is as follows: the brushless DC motor is started by the motor controller and runs according to the set operating steps so that the brushless DC motor runs normally and reports a fault if it cannot run normally.

[0007] A further improvement of the method for improving the starting performance of the air pump in an air suspension system according to the present invention is that the setting operation steps include the following steps: The brushless DC motor is started by the motor controller to drive the piston to rotate forward / reverse. If the start is successful, the brushless DC motor will run normally. If the start fails, the brushless DC motor will be started through the motor controller to drive the piston to rotate in reverse / forward. If the start is successful, the brushless DC motor will run normally. If startup fails, the brushless DC motor will stop starting and a fault report will be displayed.

[0008] A further improvement of the method for improving the starting performance of the air pump in an air suspension system according to the present invention is that the setting operation steps include the following steps: S21. The brushless DC motor is started via the motor controller to drive the piston to rotate forward / reverse: If the startup is successful, the brushless DC motor will run normally. If the start fails, the brushless DC motor is started via the motor controller to drive the piston to rotate in reverse / forward by a certain angle. If the rotation is successful, the process returns to step S21. If the rotation fails, the start of the brushless DC motor is stopped and a fault is reported.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes the PWM duty cycle modulation function of a brushless DC motor during startup to control the voltage supplied to the motor by the power supply module. Combined with a PID control algorithm, the PWM duty cycle is calculated based on the target speed to control the rotational speed, ensuring a smooth increase in startup speed. This, in turn, ensures a smooth increase in startup current, avoids generating spike noise, and keeps startup noise at a low level. Attached Figure Description

[0010] Fig. 1 A flowchart of the method of the present invention for improving the starting performance of the air pump in an air suspension system is shown.

[0011] Fig. 2 A flowchart illustrating one of the setting operation steps of the present invention is shown.

[0012] Fig. 3 A flowchart illustrating another setting of the operation steps of the present invention is shown. Detailed Implementation

[0013] To address the problems of high starting current, loud starting noise, and disruption to normal equipment operation caused by traditional brushed DC motors, this invention provides a method for improving the starting performance of an air pump in an air suspension system. The method is further described below with reference to specific embodiments and accompanying drawings.

[0014] See Figs. 1-3 As shown, a method for improving the starting performance of an air pump in an air suspension system includes the following steps: S1. Replace the brushed DC motor in the air pump with a brushless DC motor. The brushless DC motor is connected to a motor controller. S2. Start the brushless DC motor with a PWM duty cycle in the range of 20%-30% via the motor controller; S3. After the brushless DC motor has been running for a set time, calculate the difference between the current speed and the target speed of the brushless DC motor. S4. Based on the speed difference, the PWM duty cycle to be output in the next step is calculated using the PID algorithm, and the brushless DC motor is controlled by the motor controller to run according to the PWM duty cycle. S5. Continue executing steps S3 and S4 until the speed reaches the target speed.

[0015] By utilizing the PWM duty cycle modulation function of the brushless DC motor during startup, the voltage supplied to the motor by the power module is controlled. Combined with the PID control algorithm, the PWM duty cycle is calculated based on the target speed to control the speed, ensuring a smooth increase in starting speed. This results in a smooth increase in starting current, avoiding spike noise and keeping starting noise at a low level. This enables the normal and smooth starting of the air pump motor in the air suspension system, protecting the motor and the vehicle's power supply, ensuring the normal functioning of the system, and improving the user's driving experience.

[0016] Furthermore, in this embodiment, the motor controller starts the brushless DC motor with a 20% PWM duty cycle. Starting the motor with this relatively low PWM duty cycle and then gradually increasing it can effectively control the voltage, which is beneficial for a smooth motor start-up. By adopting the above design, it is beneficial to use the PID algorithm to accurately calculate the PWM duty cycle to be output in the next step based on the speed difference, thereby achieving precise control.

[0017] The air pump also includes a piston. The output end of the brushless DC motor is connected to the piston to drive the piston to reciprocate. There is a point of maximum resistance during the reciprocating motion of the piston. When the piston is in its initial position near the point of maximum resistance, step S2 starts the brushless DC motor by starting the brushless DC motor through the motor controller and running it according to the set operating steps to ensure that the brushless DC motor runs normally and reports a fault if it cannot run normally.

[0018] Since air-pumped pumps typically use a motor to drive a reciprocating piston, employing a check valve for directional gas delivery, the load on the piston during one revolution is not uniform. The motor will inevitably encounter a point of maximum resistance during this reciprocating motion. When the piston is near this point of maximum resistance, coupled with a heavy external gas tank load and low-temperature conditions, the motor struggles to overcome the combined resistance to start normally. Therefore, we employ a brushless DC motor, which offers more flexible commutation control. Furthermore, to avoid the pump's maximum resistance point, a bidirectional control strategy is adopted. This application provides the following two operating steps: See Fig. 2 As shown, one of the setup and operation steps includes the following steps: The brushless DC motor is started by the motor controller to drive the piston to rotate forward / reverse. If the start is successful, the brushless DC motor will run normally. If the start fails, the brushless DC motor will be started through the motor controller to drive the piston to rotate in reverse / forward. If the start is successful, the brushless DC motor will run normally. If startup fails, the brushless DC motor will stop starting and a fault report will be displayed.

[0019] By adopting the above design, when the brushless DC motor is started to drive the piston to rotate forward, if the start is successful, the brushless DC motor will run normally. If the start fails, it means that the forward rotation of the piston is hindered by the point of maximum resistance, resulting in the start failure. At this time, the brushless DC motor can be started to drive the piston to rotate in reverse, thus realizing the start and operation of the brushless DC motor.

[0020] See Fig. 3 As shown, another setup and operation procedure includes the following steps: S21. The brushless DC motor is started via the motor controller to drive the piston to rotate forward / reverse: If the startup is successful, the brushless DC motor will run normally. If the start fails, the brushless DC motor is started via the motor controller to drive the piston to rotate in reverse / forward by a certain angle. If the rotation is successful, the process returns to step S21. If the rotation fails, the start of the brushless DC motor is stopped and a fault is reported.

[0021] By adopting the above design, the brushless DC motor is first started to drive the piston to rotate forward. If the start is successful, the brushless DC motor will run normally. If the start fails, it means that the point of maximum resistance is blocking the piston's forward rotation path. At this time, the brushless DC motor can be started by the motor controller to drive the piston to rotate in reverse at a certain angle, so that the piston is away from the point of maximum resistance. Then the brushless DC motor is started again to drive the piston to rotate forward until the start is successful or the rotation fails. This method effectively overcomes the problem of the motor being difficult to start when the piston is close to the point of maximum resistance.

[0022] Furthermore, in this embodiment, the angle is 180 degrees.

[0023] By adopting the above design, the rotation angle is 180 degrees, which can effectively keep the piston away from the point of maximum resistance, which is beneficial for the motor to start working; in other embodiments, the angle can also be 90 degrees, 60 degrees, 30 degrees, etc.

[0024] Among them, the brushless DC motor is a three-phase brushless DC motor. The UVW three-phase drive half-bridge in the three-phase brushless DC motor achieves forward rotation in the order of WV, WU, VU, VW, UW, UV, WV, and reverse rotation in the order of WV, UV, UW, VW, VU, WU, WV.

[0025] By adopting the above design, it is convenient to control the brushless DC motor to rotate clockwise (forward) and counterclockwise (reverse).

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for improving the starting performance of an air suspension system, characterized in that The method comprises the following steps: S1, replacing a brush DC motor in the inflator pump with a brushless DC motor, the brushless DC motor being connected with a motor controller; S2, starting the brushless DC motor to run by the motor controller at a duty cycle in a 20%-30% PWM range; S3, calculating a difference between a current rotating speed of the brushless DC motor and a target rotating speed after the brushless DC motor runs for a set time; S4, calculating a PWM duty cycle to be output next by a PID algorithm according to the rotating speed difference and controlling the brushless DC motor to run according to the PWM duty cycle by the motor controller; S5, continuously executing the steps S3 and S4 until the rotating speed reaches the target rotating speed.

2. The method for improving the air suspension system in the air pump start performance of claim 1, characterized in that, The inflator pump further comprises a piston, an output end of the brushless DC motor being connected with the piston for driving the piston to reciprocate, the piston having a maximum resistance point in the reciprocating process; When the initial position of the piston is close to the maximum resistance point, the step S2 starts the brushless DC motor by the motor controller to run according to a set running step, so that the brushless DC motor runs normally and reports a fault when it cannot run normally.

3. The method for improving the air suspension system in the air pump start performance of claim 2, characterized in that, The set running step comprises the following steps: starting the brushless DC motor to run in a forward / reverse direction by the motor controller, if the starting is successful, the brushless DC motor runs normally; if the starting fails, starting the brushless DC motor to run in a reverse / forward direction by the motor controller, if the starting is successful, the brushless DC motor runs normally; if the starting fails, stopping the brushless DC motor and reporting a fault.

4. The method for improving the air suspension system in the air pump start performance of claim 2, characterized in that, The set running step comprises the following steps: S21, starting the brushless DC motor to run in a forward / reverse direction by the motor controller: if the starting is successful, the brushless DC motor runs normally; if the starting fails, starting the brushless DC motor to run in a reverse / forward direction by the motor controller: if the starting is successful, returning to the step S21; if the starting fails, stopping the brushless DC motor and reporting a fault.

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