CN108423066B - Hydraulic steering control system and method for agricultural wheeled tractor - Google Patents
Hydraulic steering control system and method for agricultural wheeled tractor Download PDFInfo
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- CN108423066B CN108423066B CN201810117103.4A CN201810117103A CN108423066B CN 108423066 B CN108423066 B CN 108423066B CN 201810117103 A CN201810117103 A CN 201810117103A CN 108423066 B CN108423066 B CN 108423066B
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- 239000003921 oil Substances 0.000 description 38
- 239000010720 hydraulic oil Substances 0.000 description 16
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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
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/09—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by means for actuating valves
- B62D5/091—Hydraulic steer-by-wire systems, e.g. the valve being actuated by an electric motor
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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
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/065—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by specially adapted means for varying pressurised fluid supply based on need, e.g. on-demand, variable assist
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
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- Guiding Agricultural Machines (AREA)
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Abstract
本发明涉及农用机械技术领域，公开了一种农用轮式拖拉机液压转向控制系统与方法，以提高转向的灵敏性和操作稳定性，降低转向的劳动强度。本发明系统包括：中控ECU，用于根据电信号连接的转角传感器、转矩传感器及角度传感器的输入信息控制双动力线控液压转向组件提供匹配的助力，该双动力线控液压转向组件包括：活塞的传动输出与转向车轮关联的液压油缸，连接有左右两条单向循环的油路，各条油路上分别部署有液压泵、单向阀和油压传感器，且还设置有位移传感器以采集该活塞根据该两条油路所应变的左右位移信息；且各该液压泵、油压传感器及位移传感器与该中控ECU电信号连接以形成车轮转角的闭环控制链路。
The invention relates to the technical field of agricultural machinery, and discloses a hydraulic steering control system and method for an agricultural wheeled tractor, so as to improve the sensitivity and operation stability of steering and reduce the labor intensity of steering. The system of the invention includes: a central control ECU, which is used for controlling the dual-power wire-controlled hydraulic steering assembly to provide matching assistance according to the input information of the rotation angle sensor, the torque sensor and the angle sensor connected with the electrical signal, and the dual-power wire-controlled hydraulic steering assembly includes: : The hydraulic cylinder associated with the transmission output of the piston and the steering wheel is connected with two one-way circulation oil circuits on the left and right. Each oil circuit is equipped with a hydraulic pump, a one-way valve and an oil pressure sensor. Collect the left and right displacement information of the piston according to the strain of the two oil circuits; and each of the hydraulic pump, oil pressure sensor and displacement sensor is connected with the central control ECU electrical signal to form a closed-loop control link of the wheel angle.
Description
Technical Field
The invention relates to the technical field of agricultural machinery, in particular to a hydraulic steering control system and method for an agricultural wheeled tractor.
Background
The working environment of the agricultural wheeled tractor is relatively severe, and particularly the working environment of the agricultural wheeled tractor with medium and small power needs to be changed frequently. As for the wheel tractor, the rolling resistance is large, the steering is heavy, the operator is easy to feel fatigue during driving, and potential safety hazards are caused. Therefore, it is particularly important to design a steering control system suitable for an agricultural wheeled tractor, to improve steering sensitivity and operation stability, and to reduce the labor intensity of steering.
Disclosure of Invention
The invention aims to disclose a hydraulic steering control system and method for an agricultural wheeled tractor, which aim to improve the steering sensitivity and the operation stability and reduce the steering labor intensity.
In order to achieve the above object, the present invention discloses a hydraulic steering control system for an agricultural wheeled tractor, comprising:
the steering angle sensor and the torque sensor are deployed on the steering column and used for acquiring a steering torque signal and a steering angle signal transmitted by the steering wheel; the steering column is physically connected with the steering wheel;
the angle sensor is deployed on the wheel and used for acquiring actual angle change information of the wheel;
the central control ECU is used for controlling the dual-power hydraulic steering-by-wire assembly to provide matched assistance according to the input information of the corner sensor, the torque sensor and the angle sensor which are connected by electric signals, and the dual-power hydraulic steering-by-wire assembly comprises:
the hydraulic oil cylinder is connected with a left oil circuit and a right oil circuit which are in one-way circulation, and the transmission output of the piston is associated with a steering wheel; and each hydraulic pump, the oil pressure sensor and the displacement sensor are in electric signal connection with the central control ECU to form a closed-loop control link of the wheel rotation angle.
Preferably, the control ECU of the present invention is further electrically connected to a road sensing motor, which is electrically connected to a hydraulic motor, and the hydraulic motor is associated with the steering wheel via a middleware to form a road sensing closed-loop control link to achieve proportional reverse transmission of the ground acting force to a driver operating the steering wheel.
Preferably, the steering wheels comprise a left steering wheel and a right steering wheel, and a steering tie rod is connected between the left steering wheel and the right steering wheel; correspondingly, the central control ECU is further configured to: and judging whether to drive the two oil ways to work simultaneously or only drive a single oil way to work according to the input information of the corner sensor, the torque sensor and the angle sensor, and distributing the two oil ways to provide the same power assistance when the two oil ways provide the steering power assistance simultaneously so as to avoid the interference of the steering tie rod.
Furthermore, the central control ECU is further configured to replace the dual-power hydraulic steer-by-wire assembly with a steering power pump to provide power for steering to act on the steering column when the current driving route is judged to be slightly deviated during straight driving.
Corresponding to the system, the invention also discloses a hydraulic steering control method of the agricultural wheeled tractor, which comprises the following steps:
the central control ECU controls the dual-power line control hydraulic steering assembly to provide matched assistance according to input information of a corner sensor, a torque sensor and an angle sensor which are connected by electric signals; and
and in the process of providing the assistance, the central control ECU forms closed-loop control of the wheel rotation angle according to the hydraulic pump, the oil pressure sensor and the displacement sensor which are connected by electric signals.
In the same way, the central control ECU preferably proportionally and reversely transmits the ground acting force to the driver operating the steering wheel according to a road sense closed-loop control link connected by an electric signal.
And when the two oil paths simultaneously provide the steering assistance, the assistance provided by the two oil paths is distributed to be consistent in magnitude so as to avoid interference of a steering tie rod connecting two steering wheels.
Or when the control ECU judges that the current running route is slightly deviated during straight running, the steering power pump replaces the dual-power hydraulic steer-by-wire assembly to provide power for steering and the power is acted on the steering column.
The invention has the following beneficial effects:
in the steering process, a closed-loop control link of a wheel corner is formed based on the dual-power line-control hydraulic steering assembly, matched power is provided, the steering sensitivity and the steering stability are improved, and the steering labor intensity is reduced.
The present invention will be described in further detail below with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic view of a portion of an agricultural wheeled tractor according to an embodiment of the present invention;
fig. 2 is a schematic signal transmission diagram of a road sensing control part disclosed by the embodiment of the invention;
fig. 3 is a partial control flow diagram of the central control ECU disclosed in the embodiment of the present invention.
Detailed Description
The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.
Example 1
The embodiment discloses a hydraulic steering control system of an agricultural wheeled tractor.
Referring to fig. 1, the hydraulic steering control system for an agricultural wheeled tractor disclosed in the present embodiment includes:
the steering system comprises a steering wheel 1, a steering shaft 2, a steering universal joint 3, a coupling 4, a torque sensor 5, a rotation angle sensor 6, a road sensing motor 7, a hydraulic motor 8, a servo valve 9, a first hydraulic oil tank 10, a steering tie rod 11, a displacement sensor (also called steering cylinder displacement sensor) 12, a hydraulic oil cylinder (also called steering cylinder) 13, a hydraulic steering tie rod 14, tires 15, an angle sensor 16, an oil pressure sensor 17, a one-way valve 18, a hydraulic pump 19, a central control ECU (also called central control system ECU) 20, a power steering pump 21 and a second hydraulic oil tank 22.
The steering angle sensor and the torque sensor are arranged on a steering column and used for collecting steering torque signals and steering angle signals transmitted by a steering wheel; the steering column is physically connected with the steering wheel;
the angle sensor is arranged on the wheel and used for acquiring actual angle change information of the wheel;
and the central control ECU is used for controlling the dual-power hydraulic steering-by-wire assembly to provide matched assistance according to the input information of a corner sensor, a torque sensor and an angle sensor which are connected by electric signals, and the dual-power hydraulic steering-by-wire assembly comprises:
the hydraulic oil cylinder is connected with a left oil circuit and a right oil circuit which are in one-way circulation, and the transmission output of the piston is associated with the steering wheel; and each hydraulic pump, the oil pressure sensor and the displacement sensor are in electric signal connection with the central control ECU to form a closed-loop control link of the wheel rotation angle. Preferably, as shown in figure 1, the hydraulic rams are also connected with servo valves to control flow and ensure safety of the system, and the drive output of the pistons is associated with the steerable wheels via hydraulic tie rods.
In addition to forming a closed-loop control link of one wheel of corner, the system of the embodiment is characterized in that the central control ECU is further electrically connected with a road sensing motor, the road sensing motor is electrically connected with a hydraulic motor, and the hydraulic motor is associated with a steering wheel through an intermediate piece (as shown in FIG. 1, the hydraulic motor specifically comprises a steering universal joint physically connected with a steering column and a coupler physically connected with the hydraulic motor, and the steering universal joint is physically connected with the coupler) so as to form the road sensing closed-loop control link and realize reverse transmission of ground acting force to a driver operating the steering wheel in proportion. Referring to fig. 1, fig. 2 and fig. 3, the working principle of the two closed-loop control links of this embodiment is as follows:
when a driver of the wheeled tractor operates the tractor, the steering wheel is rotated, the steering wheel drives the steering shaft to work synchronously, and the steering shaft is convenient to steer under the auxiliary action of the power steering pump. When the steering shaft works, the steering shaft is connected with a steering coupling through a steering universal joint, a torque sensor and a corner sensor are arranged below the coupling, the torque sensor can detect a steering torque signal of a steering wheel, the corner sensor can detect a corner signal of the steering wheel, meanwhile, a central control ECU receives the signals of the torque sensor and the corner sensor, and sends a control signal to a road feel motor together with the signal of an actual steering angle sensor of wheels through a central control system ECU, and the road feel motor receives a feedback signal and outputs torque according to a certain proportion so as to give a road surface operation road feel corresponding to a driver.
Meanwhile, the central control ECU judges whether to drive two oil ways to work simultaneously or only drive a single oil way to work according to the input information of the corner sensor, the torque sensor and the angle sensor. When two oil paths work simultaneously, a resultant force of one pile and one pull is generated, and when a single oil path works independently, the other oil path does not provide assistance. The left and right movement of a piston of the hydraulic oil cylinder is realized by double hydraulic pumps, and the left and right double hydraulic pumps are controlled by a central control ECU to realize that two oil paths respectively work in a single-way circulation mode. For example: when the right hydraulic pump is driven by the central control ECU to work, the hydraulic pump sucks hydraulic oil from the first hydraulic oil tank and turns the hydraulic oil to high pressure from low pressure, and the high-pressure hydraulic oil enters the right end of the hydraulic oil cylinder through the one-way valve, so that the steering is realized; in this process, oil pressure sensor monitors hydraulic pump output oil pressure height in step, because the check valve can only one-way work, the effect of check valve promptly makes right hydraulic pump to the steering cylinder have the effect of one-way UNICOM, and right hydraulic pump during operation can not make the left side hydraulic pump produce the influence. And the high-pressure hydraulic oil flows back to the first hydraulic oil tank again after flowing through the steering oil cylinder. The operation of the left oil path is similar to that of the left oil path, and is not described in detail.
Further, as shown in fig. 1, in this embodiment, the steered wheels include a left steered wheel and a right steered wheel, and a tie rod is connected between the left steered wheel and the right steered wheel, so that the wheels on one side are steered and operate through the tie rod, and thus the wheels on the other side are driven to correspondingly steer, and wheel deflection is realized. Therefore, when the two oil passages simultaneously provide the steering power assistance, the central control ECU preferably distributes the power assistance provided by the two oil passages to be consistent in magnitude so as to avoid interference of the tie rods.
In the actual operation of the wheeled tractor, the accuracy of the output of the steering torque and the steering angle are required to be ensured to meet the high-precision requirement, and a certain road feeling can be brought to a driver, so that the characteristic of comfortable and soft steering is realized. The embodiment is mainly characterized in that the steering angle and the torque are organically combined, the accuracy of the output torque of the road sensing motor is ensured, and the error fluctuation of the corner output and the execution is controlled, so that the corner output of the wheeled tractor is ensured to be smooth. Meanwhile, in the steering process, the central control system ECU can perform internal calculation and correction processing according to various sensing signals such as a displacement sensor, an angle sensor on a tire, a corner sensor, a torque sensor and an oil pressure sensor, and the dynamic response characteristic of steering output is improved.
As shown in fig. 1, the agricultural wheeled tractor of this embodiment further includes a power steering pump, and the power steering pump is connected to the central control ECU and the second hydraulic oil tank, so that when the central control ECU determines that the current driving route is slightly deviated during straight driving, the power steering pump is used to replace the dual-power steer-by-wire hydraulic steering assembly to provide power for steering to act on the steering column.
Example 2
Corresponding to the above embodiments, the present embodiment discloses a hydraulic steering control method for an agricultural wheeled tractor, including:
the central control ECU controls the dual-power line control hydraulic steering assembly to provide matched assistance according to input information of a corner sensor, a torque sensor and an angle sensor which are connected by electric signals; and
in the process of providing the boosting force, the central control ECU forms closed-loop control of the wheel rotation angle according to the hydraulic pump, the oil pressure sensor and the displacement sensor which are connected by electric signals.
In the same way, the central control ECU also preferably proportionally transmits the ground acting force in the opposite direction to the driver operating the steering wheel according to a road sense closed-loop control link connected by an electric signal.
In the method of this embodiment, the central control ECU further includes:
and judging whether to drive two oil ways in the dual-power hydraulic steer-by-wire assembly to work simultaneously or only drive a single oil way to work according to the input information of the angle sensor, the torque sensor and the angle sensor, and distributing the assistance forces provided by the two oil ways to be consistent when the two oil ways provide the steering assistance force simultaneously so as to avoid the interference of a steering tie rod connecting two steering wheels.
Or, in the embodiment, when the control ECU determines that the current driving route is slightly deviated from the straight driving route, the steering power pump is used for replacing the dual-power hydraulic steer-by-wire assembly to provide the power for steering to act on the steering column.
For a person skilled in the art to fully understand the solution of the present invention, reference is made to fig. 1, fig. 2 and fig. 3, and the following is exemplified:
when a driver drives a tractor and runs in a straight line, a steering wheel only slightly stores a corner with certain degree of freedom, and a corner sensor on a steering column can detect and feed back to a central control ECU. However, if the tractor tire is deflected at this time (under the condition that the hydraulic pump is not operated), the tire deflection angle is also detected by the tire angle sensor. At this time, the central control system calculates and corrects by combining with the multi-dimensional parameter optimization, and finally calculates a proper turning angle value. The turning angle value is larger than a certain value, a driver can find deviation, if the deviation is caused, the driver necessarily rotates a steering wheel to correct a route, the turning angle value becomes an electric signal applied by a steering power pump by a central control system, the working flow of the steering power pump is output and becomes the power for steering, the power is increased, when the steering power pump is driven linearly, the route is subjected to deviation (slight deviation) angle calculation to form an electric parameter and finally is supplied to the steering power pump, the lower hydraulic pump does not work at the moment because the steering power pump is only slightly deviated when the steering power pump is driven linearly.
When the driver operates the steering wheel to turn left, the left hydraulic pump starts to work, the flow rate of the work of the hydraulic pump firstly comes from the central control ECU to detect the electric parameters of a turning angle sensor and a torque sensor on the steering column, and the electric parameters are instantaneous signals and are quick in response. The central control ECU collects signals of various sensors at the same time, outputs an execution signal to the hydraulic pump, the hydraulic pump starts to work, the piston of the hydraulic oil cylinder moves to the left, the left tire rotates around the steering main pin, and the right tire is driven to rotate together through the steering tie rod. Normally, a single hydraulic pump operates in the case where the steering angle is not large. In the working process, a hydraulic oil cylinder displacement sensor and an angle sensor are used for actually detecting the transverse displacement and the angle of the specific deflection of the tire; then comparing signals of a corner sensor and a torque sensor on a steering column at the initial stage, wherein the signals are bound to have difference (parameter errors exist because the signals pass through mechanical structures such as universal joints, couplings and the like in the middle); therefore, the central control ECU detects the parameters of the angle sensor, the displacement sensor and the oil pressure sensor of the tire again, and then adjusts the output flow of the oil pump timely and continuously after correction. And at this moment, the steering wheel can change constantly according to the intention of the driver, and can not stop until the driving steering purpose of the driver is realized, so in the process, the rotation angle sensor on the steering column, the angle sensor of the tire, the torque sensor on the steering column, the oil pressure sensor of the tire and the oil cylinder displacement sensor feed back and adjust and correct each other, and the matching is completed. In the middle steering process, a driver holds the steering wheel and feels a relative acting force from the road sensing motor, the hydraulic motor drives the road sensing motor to output, and the acting force is output according to a certain proportion, so that the driver feels that a ground acting force is transmitted to the steering wheel from the road surface. In particular, if the cylinder oil pressure is too high, the servo valve starts to operate, thereby synchronously adjusting the operating pressure or the operating flow rate of the hydraulic pump and returning the oil exceeding the rated amount to the first hydraulic tank. If the steering angle is larger than a certain value, the left hydraulic pump and the right hydraulic pump work simultaneously at the moment, namely one hydraulic pump pushes and one hydraulic pump pulls to realize double-power steering, and the steering angle is light when large.
In summary, the hydraulic steering control system and method for the agricultural wheeled tractor disclosed by the embodiment of the invention form a closed-loop control link of the wheel turning angle and provide matched power based on the dual-power wire control hydraulic steering assembly in the steering process, thereby improving the steering sensitivity and the operation stability and reducing the steering labor intensity.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
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| CN201810117103.4A CN108423066B (en) | 2018-02-06 | 2018-02-06 | Hydraulic steering control system and method for agricultural wheeled tractor |
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| CN201810117103.4A CN108423066B (en) | 2018-02-06 | 2018-02-06 | Hydraulic steering control system and method for agricultural wheeled tractor |
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| CN109291991B (en) * | 2018-12-01 | 2023-10-24 | 南京天航智能装备研究院有限公司 | Dual-motor drive-by-wire composite steering system and control method thereof |
| CN111301516A (en) * | 2020-02-28 | 2020-06-19 | 常熟理工学院 | Electric vehicle wheel hub motor-driven steer-by-wire modification method |
| CN118493920B (en) * | 2024-07-17 | 2024-12-24 | 福建建阳龙翔科技开发有限公司 | Hydraulic pressure branch accuse mechanism of large-scale tire building machine |
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| DE102008021973A1 (en) * | 2008-05-02 | 2009-11-05 | Bayerische Motoren Werke Aktiengesellschaft | Vehicle steering system of the by-wire design |
| JP5607583B2 (en) * | 2011-07-12 | 2014-10-15 | 日立オートモティブシステムズステアリング株式会社 | Power steering device |
| KR101646391B1 (en) * | 2014-11-27 | 2016-08-05 | 현대자동차주식회사 | Control method for electro hydraulic power steering system |
| CN107628104A (en) * | 2017-08-30 | 2018-01-26 | 芜湖中意液压科技股份有限责任公司 | The double-power hydraulic steering boost system of hybrid power passenger car |
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