CN110816642A - Control method and system for electro-hydraulic power steering under low-temperature working condition - Google Patents
Control method and system for electro-hydraulic power steering under low-temperature working condition Download PDFInfo
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- CN110816642A CN110816642A CN201810899096.8A CN201810899096A CN110816642A CN 110816642 A CN110816642 A CN 110816642A CN 201810899096 A CN201810899096 A CN 201810899096A CN 110816642 A CN110816642 A CN 110816642A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
- B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
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- Mechanical Engineering (AREA)
- Steering Control In Accordance With Driving Conditions (AREA)
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Abstract
The invention relates to a control method and a system for electro-hydraulic power steering under a low-temperature working condition. Comprising a processor and a memory, the processor executing program instructions stored in the memory to implement the steps of: when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency. When the electric power-assisted steering oil pump is started every time, the steering motor operates for a period of time at a speed higher than the rated speed, hydraulic oil in a steering oil way is effectively circulated, the activity of the hydraulic oil is improved, and a steering hydraulic system is preheated. Therefore, the problem that the vehicle with the EHPS cannot be started quickly due to long preheating time when the temperature is low is solved.
Description
Technical Field
The invention relates to the technical field of vehicle power-assisted steering, in particular to a control method and a system for electro-hydraulic power-assisted steering under a low-temperature working condition.
Background
An electric hydraulic power-assisted steering system, EHPS for short, adopts a steering motor and a controller to drive a steering oil pump (electric steering oil pump for short), and directly performs steering power assistance on the whole vehicle through hydraulic energy provided by the steering oil pump. The hybrid power system is widely applied to new energy automobiles, particularly pure electric automobiles and deep hybrid electric automobiles. However, current EHPS has the following characteristics: because the whole vehicle has no engine, the electric steering oil pump and the hydraulic system can not be preheated by the waste heat of the engine, so that when the temperature in a cold region is lower, the viscosity of the hydraulic steering oil is higher, the electric steering oil pump system is poor, the working sound is large, the oil pressure is slow to build, and the steering wheel has heavy hand feeling. Especially, when the steering oil enters water vapor or other impurities, the condensation point is increased, the steering oil originally becomes pasty when being in a liquid state at a low temperature, so that the electric steering oil pump can absorb oil more poorly, air is sucked into an oil path to generate explosion sound, a driver needs to drive the whole vehicle, the steering wheel has heavy hand power or no steering power, the steering oil pump has large working sound, and the normal driving of the driver is influenced.
At present, most of electric commercial vehicles adopting EHPS (electric steering pump) have low environmental temperature, most drivers need to lead the electric steering oil pump to work for a long time in advance before the whole vehicle is operated, the aim is to preheat a hydraulic system, after the steering hydraulic oil is preheated, the steering oil pump starts to absorb oil, the working sound is reduced, the whole vehicle can be normally driven when the hand force of a steering wheel is recovered, the steering hydraulic oil way is circulated by the electric steering oil pump, so that the hydraulic oil way preheating method is realized, the heat source energy of the electric steering oil pump is low, the preheating time is long, and the effect is poor.
Disclosure of Invention
The invention aims to provide a control method and a control system for electro-hydraulic power steering under a low-temperature working condition, and aims to solve the problems that when the temperature is low, the preheating time is long, and a vehicle provided with an EHPS (electric hydraulic power steering) cannot be started quickly.
In order to solve the technical problems, the technical scheme of the invention is as follows:
the invention provides a control method of electro-hydraulic power steering under a low-temperature working condition, which comprises the following steps of:
when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency.
The invention also provides a control system of the electro-hydraulic power steering under the low-temperature working condition, which comprises a processor and a memory, wherein the processor executes the program instructions stored in the memory to realize the following steps:
when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency.
Has the advantages that:
under the condition that hardware such as any sensor is not added, the steering motor is controlled by combining with the actual working condition, when a vehicle is started, the steering motor works under the condition that the frequency is higher than the rated frequency, so that the steering oil way is effectively circulated, the activity of the steering oil way is improved, and the steering hydraulic system is preheated. The problem that a vehicle with an EHPS cannot be started quickly due to long preheating time when the temperature is low is solved.
For a further improvement of the method and system, the preset time is inversely proportional to the ambient temperature, the lower the ambient temperature, the longer the length of the preset time.
For a further development of the method and system, after the predetermined time has elapsed, the steering motor is operated at a frequency which is lower than the nominal frequency.
For further improvement of the method and the system, when the steering motor runs at a reference frequency, the working current of the motor is detected to be greater than or equal to the frequency-increasing current threshold value and continuously increases the frequency for a preset time, the steering motor controller controls the steering motor to run at a rated frequency, and the reference frequency is the lowest working frequency of the steering motor;
when the steering motor runs at a rated frequency, detecting that the working current of the steering motor is less than or equal to a frequency reduction current threshold value and continuously reducing the frequency for a preset time, and controlling the steering motor to run at a reference frequency by a steering motor controller; according to the actual requirement of the actual vehicle on the steering hydraulic energy, the steering motor is controlled to provide power according to the requirement, and the problems of heavy steering wheel caused by insufficient oil supply of the driving steering oil pump or poor hand feeling, drifting and the like of the steering wheel caused by excessive oil supply are avoided.
Drawings
FIG. 1 is a schematic diagram of an electro-hydraulic power steering system according to an embodiment;
FIG. 2 is a flow chart of the method in the example.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
The basic principle of the invention is as follows:
when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency. When the electric power-assisted steering oil pump is started every time, the steering motor operates for a period of time at a speed higher than the rated speed, hydraulic oil in a steering oil way is effectively circulated, the activity of the hydraulic oil is improved, and a steering hydraulic system is preheated. Therefore, the problem that the vehicle with the EHPS cannot be started quickly due to long preheating time when the temperature is low is solved.
Specifically, the method comprises the following steps:
a control system of electro-hydraulic power steering under low-temperature working conditions is characterized in that as shown in figure 1, a power supply source of a steering motor is connected with a steering motor controller, the steering motor controller is connected with an entire vehicle ECU and a steering motor M, the steering motor M and an oil pump form an electric power steering oil pump, the oil pump is connected with a liquid storage device and a hydraulic steering gear, and the hydraulic steering gear is further connected with a steering wheel and a steering output shaft. The entire vehicle ECU (or other independently disposed processor or processing chip) is configured to execute corresponding program instructions to implement the method shown in fig. 2:
the method comprises the following specific steps: when a vehicle is started, the steering motor controller controls the steering motor to run at a first frequency, namely a frequency higher than a rated frequency, within 10s, so that hydraulic oil of a steering oil way is effectively circulated, the activity of the hydraulic oil is improved, a steering hydraulic system is indirectly preheated, and the quick oil absorption capacity of a cold region is improved; the oil pressure is quickly established, and the hydraulic hysteresis feeling is reduced.
After starting for 10s, the steering motor runs at a reference frequency (the reference frequency is the lowest frequency); when the steering motor recovers to the reference frequency, the rotating speed also recovers to the reference rotating speed (the working rotating speed corresponding to the reference frequency is the lowest rotating speed), the reference frequency and the corresponding rotating speed are reasonably calibrated according to the actual vehicle, and if the set rotating speed is too low, the steering wheel is overweight instantly or the steering hand feeling is delayed; if the setting is too high, energy consumption and working sound are large. Therefore, the working energy consumption and the noise can be effectively reduced, and the hand feeling of the steering wheel can be enhanced.
When the steering motor operates at the reference frequency, the motor controller detects the working current of the steering motor, then judgment is carried out, when the steering wheel is rotated, the pressure of a steering oil way is increased, the load of the steering motor is increased, and the working current of the steering motor is increased. And when the working current is greater than or equal to the frequency-increasing current threshold and the duration time exceeds the frequency-increasing preset time, the steering motor controller controls the steering motor to operate according to the rated frequency (corresponding to the rated rotating speed). The frequency-increasing current threshold is higher than the working current value of the steering motor under the working of the reference frequency, namely when the working current reaches the frequency-increasing current threshold, the steering motor operates at the increased frequency.
When the vehicle speed is higher, the steering wheel operation angle of a driver is small, or the steering wheel is in the return position and other working conditions, the steering hydraulic energy consumption is lower, the pressure of a steering oil way is lower, the load of a steering motor is reduced accordingly, and the working current is reduced. When the steering motor runs at the rated frequency and the working current is less than or equal to the frequency reduction current threshold and the duration time exceeds the frequency reduction preset time, the steering motor controller controls the steering motor to run according to the reference frequency (corresponding to the reference rotating speed). The frequency-reducing current threshold is lower than the working current value of the steering motor under the rated frequency operation, namely when the working current is less than or equal to the frequency-reducing current threshold, the frequency of the steering motor is reduced to the reference frequency for operation.
The purpose of this steering motor frequency control is: according to the actual requirement of the actual vehicle on the steering hydraulic energy, the steering motor is controlled to provide power according to the requirement, and the problems of heavy steering wheel caused by insufficient oil supply of the driving steering oil pump or poor hand feeling, drifting and the like of the steering wheel caused by excessive oil supply are avoided.
The design of the rated frequency and the corresponding rotating speed is related to the design parameters of the steering motor and the steering oil pump so as to meet the requirements of reasonable rated steering, reasonable steering oil pump displacement and various working conditions of the real vehicle. The design of reference frequency and reference rotating speed is an effective and reasonable design combining control response time and oil circuit pressure building time, and effective calibration and verification are carried out through a real vehicle
As another embodiment, when the vehicle is started, the preset time in the method may be adjusted according to the actual working environment of the steering motor. For example, it is not limited to 10s in the present embodiment.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.
Claims (8)
1. A control method for electro-hydraulic power steering under a low-temperature working condition is characterized by comprising the following steps of:
when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency.
2. The method as claimed in claim 1, wherein the preset time is inversely proportional to the ambient temperature, and the lower the ambient temperature is, the longer the preset time is.
3. The method for controlling the electro-hydraulic power steering under the low temperature condition according to claim 1 or 2, wherein after the preset time, the steering motor is operated at a frequency lower than the rated frequency.
4. The method for controlling the electro-hydraulic power steering under the low-temperature working condition according to claim 3, wherein when the steering motor operates at a reference frequency, the steering motor controller controls the steering motor to operate at a rated frequency when detecting that the motor operating current is greater than or equal to an up-frequency current threshold value and the up-frequency current continues for a preset up-frequency time, wherein the reference frequency is the lowest operating frequency of the steering motor;
when the steering motor runs at the rated frequency, the steering motor controller controls the steering motor to run at the reference frequency by detecting that the working current of the steering motor is less than or equal to the frequency reduction current threshold and continuously reducing the frequency for preset time.
5. A control system for electro-hydraulic power steering under low temperature conditions, comprising a processor and a memory, wherein the processor executes program instructions stored in the memory to perform the steps of:
when the steering motor is started, the steering motor is controlled to run at a first frequency higher than the rated frequency within a preset time, and after the preset time related to the ambient temperature, the steering motor is controlled to run at a reduced frequency.
6. The electro-hydraulic power steering control system under low temperature conditions of claim 5, wherein the preset time is inversely proportional to the ambient temperature, and the lower the ambient temperature is, the longer the preset time is.
7. The electro-hydraulic power steering control system under low temperature conditions of claim 5 or 6, wherein after a preset time, the steering motor is operated at a frequency lower than the rated frequency.
8. The electro-hydraulic power steering control system under the low-temperature working condition according to claim 7, wherein when the steering motor operates at a reference frequency, the steering motor controller controls the steering motor to operate at a rated frequency when detecting that the motor operating current is greater than or equal to an up-frequency current threshold value and the up-frequency current continues for a preset up-frequency time, and the reference frequency is the lowest operating frequency of the steering motor;
when the steering motor runs at the rated frequency, the steering motor controller controls the steering motor to run at the reference frequency by detecting that the working current of the steering motor is less than or equal to the frequency reduction current threshold and continuously reducing the frequency for preset time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810899096.8A CN110816642A (en) | 2018-08-08 | 2018-08-08 | Control method and system for electro-hydraulic power steering under low-temperature working condition |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810899096.8A CN110816642A (en) | 2018-08-08 | 2018-08-08 | Control method and system for electro-hydraulic power steering under low-temperature working condition |
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| CN110816642A true CN110816642A (en) | 2020-02-21 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101516714A (en) * | 2006-09-15 | 2009-08-26 | 丰田自动车株式会社 | Vehicle steering control system and control method therefor |
| US20110190986A1 (en) * | 2010-02-04 | 2011-08-04 | Nissan Motor Co., Ltd. | Working fluid medium temperature control system and method |
| US20140136053A1 (en) * | 2012-11-12 | 2014-05-15 | Toyota Jidosha Kabushiki Kaisha | Steering apparatus and control method thereof |
| CN104890722A (en) * | 2015-05-15 | 2015-09-09 | 郑州宇通客车股份有限公司 | Control method of electro-hydraulic power-assisted steering and system for implementing method |
| CN106428194A (en) * | 2016-09-06 | 2017-02-22 | 郑州宇通客车股份有限公司 | Control method of electro-hydraulic power steering based on factor compensation |
-
2018
- 2018-08-08 CN CN201810899096.8A patent/CN110816642A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101516714A (en) * | 2006-09-15 | 2009-08-26 | 丰田自动车株式会社 | Vehicle steering control system and control method therefor |
| US20110190986A1 (en) * | 2010-02-04 | 2011-08-04 | Nissan Motor Co., Ltd. | Working fluid medium temperature control system and method |
| US20140136053A1 (en) * | 2012-11-12 | 2014-05-15 | Toyota Jidosha Kabushiki Kaisha | Steering apparatus and control method thereof |
| CN104890722A (en) * | 2015-05-15 | 2015-09-09 | 郑州宇通客车股份有限公司 | Control method of electro-hydraulic power-assisted steering and system for implementing method |
| CN106428194A (en) * | 2016-09-06 | 2017-02-22 | 郑州宇通客车股份有限公司 | Control method of electro-hydraulic power steering based on factor compensation |
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Application publication date: 20200221 |
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