CN201086737Y - Automobile Steering Servo Control System - Google Patents

Abstract

The utility model discloses a car steering servo control system. The power-assisted steering system comprises a torque controller, wherein the torque controller is provided with a plurality of power-assisted characteristic curves, the torque controller calculates basic target current and dynamic compensation target current according to vehicle speed, hand force of a steering wheel and feedback signals, and selects the power-assisted characteristic curves by adopting a closed-loop negative feedback control mode, so that the safety and the comfort of a driver can be met; adopt the utility model discloses a booster only needs the power and need not the hydraulic pressure source, and part figure is few, arranges the convenience, and light in weight can save the engine energy 3 ~ 5%, has improved the working property of car, does not have oil leakage, has reduced the possibility of oil pollution, has improved the environment, is the green product of an energy-concerving and environment-protective, high security, high travelling comfort, applicable car below the front axle load 8 tons.

Description

Automobile Steering Servo Control System

technical field

The utility model relates to a servo control system, in particular to a circulating ball worm gear steering servo control system for automobiles.

Background technique

Hydraulic power steering (HPS for short) is widely used in automobiles now. Its structure is shown in Figure 1. It consists of steering gear, high-pressure oil pump, oil tank, oil inlet pipe, oil return pipe, stroke limit valve assembly, and upstroke limit valve. It is composed of the adjusting screw and the adjusting screw of the downstroke limit valve. The hydraulic power steering gear is a hydraulic constant flow type, and its power assist characteristic curve is shown in Figure 2. After more than half a century of production and development, it has been quite mature in theory and technology and has reached a very high level, but it is difficult to meet the high efficiency, energy saving, high comfort and high safety of modern automobile technology; in terms of safety requirements, HPS When driving at high speed, the steering wheel is too light, causing the driving feeling to be floating, and the road feel is poor. This is a difficult problem for this steering gear; in terms of high efficiency and energy saving, the hydraulic constant flow type has low energy efficiency. Energy saving is the most popular topic in the world today, and improving energy utilization and saving energy is the most concerned issue. Environmental protection is also an issue that is highly valued by the world, and the oil leakage problem of HPS is also difficult to overcome.

At present, several universities, research institutes, and manufacturers are researching and developing electronically controlled hydraulic power steering (EHPS for short). In addition, EHPS is composed of two sets of hydraulic and electronic servo systems, so the structure is complicated and the cost is increased.

At present, electric power steering has begun to be used in cars in foreign countries. This kind of steering is limited to small cars with a front axle load ≤ 1 ton, such as: Cervo and Alto cars from Suzuki, Mira from Daihatsu and Mitsubishi. The company's Minica car, etc. At present, due to the limitations of the power, torque, and size of the motor, the electric power steering of the car is mostly used in light and mini cars, station wagons, and small trucks, and the scope of use is limited.

Contents of the invention

In order to overcome the deficiencies of the prior art, the utility model provides an automobile steering servo control system with simple control, excellent performance and wide application range.

The technical scheme that the utility model solves its technical problem adopts is:

Automobile steering servo control system, including the torque controller of the power steering control part, the controller includes a data processing module, the input end is connected to the state detection part that detects the vehicle's working state, the output end is connected to the motor parameter calculation module and the system fault detection module, and the parameter calculation module The output end is connected to the motor drive circuit through the parameter controller, the output end of the fault detection module is connected to the power control module of the control system, the power control module is connected to the motor drive circuit, the output end of the motor drive circuit is connected to the motor detection circuit, and the motor detection circuit feeds back the detected signal to A parameter calculation module, a parameter controller and a fault detection module.

The beneficial effects of the utility model are: the booster adopting the automobile steering servo control system only needs power supply instead of hydraulic source, the number of parts is small, the arrangement is convenient, the weight is light, and there is no "parasitic loss", which can save engine energy by 3-5% , improve the running performance of the car, there is no oil leakage, reduce the possibility of oil pollution, and improve the environment; the power assist characteristic curve of the utility model changes with the change of the car's motion status (vehicle speed, road conditions and steering wheel hand force), Therefore, it has countless assist characteristic curves, which is different from hydraulic power steering with only one fixed assist characteristic curve independent of speed, which can satisfy the safety and comfort of the driver. A comfortable green product, suitable for vehicles with a front axle load of less than 8 tons.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a diagram of a hydraulic power steering system currently used;

Fig. 2 is the boost characteristic curve of the hydraulic power steering gear used at present;

Fig. 3 is the ideal boost characteristic model of the present utility model;

Fig. 4 is a block diagram of the utility model torque controller;

Fig. 5 is the schematic diagram of the utility model embodiment;

Fig. 6 is the schematic diagram of electric current calculation of the utility model embodiment;

Figure 7 is a schematic view of the appearance of the utility model;

Fig. 8 is a schematic diagram of the structure of the utility model.

Detailed ways

With reference to Fig. 4, Fig. 5, the utility model automobile steering servo control system, comprises steering assist torque controller 3, and torque controller 3 comprises the state detection part 1 output end that detects vehicle working state and connects data processing module 21 input and exit ends, state detection Part 1 includes a torque sensor 11, a vehicle speed sensor 12 and an engine speed sensor 13, and the data processing module 21 includes an A/D converter 28 and a frequency signal catcher 33, and the output terminal of the data processing module 21 is connected to a parameter calculation module 22 and a fault detection module 24 Input terminal, parameter calculation module 22 comprises total target current calculator 31, basic target current calculator 29 and dynamic compensation target current calculator 30, basic target current calculator 29 and dynamic compensation target current calculator 30 output the result of calculation to The motor total target current calculator 31, the output end of the parameter calculation module 22 is connected to the input end of the motor drive circuit 25 through the parameter controller 26, and the determined assist current is sent to the drive circuit 25, and the drive circuit 25 is connected to the assist motor 15 to control the assist motor 15 The positive and negative rotation and the size of the torque, the power-assisted motor 15 is connected to the mechanical part 4 of the steering gear to help the manual power assist, the fault detection module 24 is connected to the power control module 23, and the control system is cut off when the system fails, without affecting the human operation.

The power control module 23 is connected to the motor drive circuit 25 to supply power to the drive circuit 25. The motor drive circuit 25 is connected to the fault detection module 24 through the motor detection circuit 27 to provide the voltage and current parameters of the motor for the fault detection module 24 to participate in fault judgment and motor detection. The circuit 27 includes an electrode voltage detection circuit 31 and an electrode voltage detection circuit 32. The motor detection circuit 27 is connected to the parameter calculation module 22 and the parameter controller 26, and uses the motor current as a negative feedback signal to realize closed-loop control.

Referring to Fig. 7 and Fig. 8, the automobile recirculating ball worm gear electric power steering includes a steering mechanical part 4, a torque controller (ECU) 3 and a booster motor 15. Steering gear mechanical part 4 comprises steering gear housing 46, steering arm shaft 47, steering nut 48, steering screw rod 49, input shaft 42, torsion bar 41, sliding sleeve 43, worm gear 44 and worm screw 45, steering wheel drives input shaft 42 to rotate, Drive the steering nut 48 to move by the steering screw rod 49, and the steering nut 48 drives the steering arm shaft 47 engaged with it to rotate, thereby driving the vertical arm to swing, making the straight rod move back and forth, and then driving the wheel to turn left and right by the horn.

Servomotor part 15 is the power source that provides boosting, and its rated power 1.5KW of the motor that the utility model adopts, rated voltage 24V, rated current 67.2A, rated torque 12N·m. The automobile recirculating ball worm gear electric power steering is calculated by the state torque controller 3 of the vehicle and selects the dynamic characteristic curve of the steering force programmed in advance to supply the current to the servo motor 15, and the main shaft of the servo motor 15 is in phase with the worm gear 45 of the reducer. Connected, the worm 45 drives the worm gear 44 meshed with it to rotate, the worm gear 44 is connected with the steering screw 49, the servo motor 15 outputs the power torque required in various states, and helps the hand force on the steering wheel to turn, and its entire control The process is done like this:

Referring to Figures 3 to 8, the steering wheel torque sensor 11 has two signals, the main signal and the auxiliary signal, and the motor current calculation uses two parts: the basic target current calculation and the dynamic target current calculation. The main signal sends the steering wheel torque signal to the basic target current calculator 29 through the A/D converter 28, and at the same time sends it to the fault detection module 24 as a parameter for fault detection, and the secondary signal is sent to the fault after passing through the A/D converter 28 The detection module 24, the vehicle speed sensor 12 converts the driving speed frequency signal catcher 33 and transmits it to the basic target current calculator 29, the dynamic compensation target current calculator 30 and the fault detection module 24, and the electric current of the motor provided by the motor current detection circuit 31 1. The voltage provided by the motor voltage detection circuit 32 is sent to the dynamic compensation target current calculator 30 and the fault detection module 24 respectively, and the basic target current calculator 29 selects the steering force dynamic characteristic curve according to the steering wheel torque signal and the driving speed signal, and calculates The basic target current, the dynamic compensation target current calculator 30 selects the dynamic compensation characteristic curve of the steering force according to the driving speed signal, the motor current, and the motor voltage, and calculates the compensation current. The compensation current calculates the total working current of the motor according to certain rules, and the calculated total current and the motor current provided by the motor current detection circuit 31 as negative feedback are transmitted to the parameter controller 26, and the parameter controller 26 transmits the calculated current to To the motor drive circuit 25, the motor drive circuit 23 drives the motor 15 to act, and the motor 15 sends different torques according to the magnitude of the supplied current to help the steering wheel move.

The fault detection module 24 judges whether the control system is normal according to the received twisting direction, torque, driving speed, motor current, motor voltage and engine speed of the steering wheel. When the system fails, the fault detection module 24 sends a signal to the power control The module 23 cuts off the power supply of the control system without affecting the operation, and at the same time sends out a fault alarm signal.

In this embodiment, the method of controlling the current parameter is used to control the torque of the electrode, of course, the method of controlling the voltage or current and voltage can also be used to control the torque of the motor. According to the signals of each sensor, the control circuit issues control commands according to a certain control strategy and vehicle working state only when the vehicle is turning and returning to the center, and sends current to the motor to implement power assist and centering control. When the steering wheel is in the middle position, the control system short-circuits the motor to perform damping motion in the positive and negative directions. Since the assist torque is determined according to the vehicle speed, resistance torque, and steering wheel torque signals, the entire system adopts closed-loop negative feedback control, and there are countless steering force characteristic curves at different vehicle speeds, which can adapt to different vehicle speeds and steering wheel torques. , Appropriate assist torque under various situations with different steering resistance torques.

Claims (4)

1. motor turning servo control unit, the torque controller (3) that comprises control part, it is characterized in that torque controller (3) comprises the state-detection part (1) of data processing module (21) input end joint detection vehicle operation state, mouth connects parameter of electric machine computing module (22) and system failure detection module (24), parameter calculating module (22) mouth connects motor-drive circuit (25) by parameter controller (26), fault detection module (24) mouth connection control system energy supply control module (23), energy supply control module (23) connects motor-drive circuit (25), motor-drive circuit (25) mouth connects motor testing circuit (27), and motor testing circuit (27) is given parameter calculating module (22) with the signal feedback that detects, parameter controller (26) and fault detection module (24).

2. motor turning servo control unit according to claim 1, it is characterized in that described parameter calculating module (22) comprises motor general objective electric current calculator (31), elementary object electric current calculator (29) and dynamic compensation target current calculator (30), elementary object electric current calculator (29) and dynamic compensation target current calculator (30) are input to motor general objective electric current calculator (31) with result calculated, by exporting after certain regular computing.

3. motor turning servo control unit according to claim 1 and 2 is characterized in that described data processing module (21) comprises A/D converter (28) and frequency signal catcher (33); Described state-detection part (1) comprises torque sensor (11), car speed sensor (12) and engine speed sensor (13); Torque sensor (11) is leaded up to A/D converter (28) and is outputed signal to elementary object electric current calculator (29), and another road outputs signal to fault detection module (24) by A/D converter (28); Car speed sensor (12) outputs signal to elementary object electric current calculator (29), dynamic compensation target current calculator (30) and fault detection module (24) respectively by frequency signal catcher (33), and engine speed sensor (13) outputs signal to fault detection module (24) by frequency signal catcher (33).

4. motor turning servo control unit according to claim 1 and 2 is characterized in that described motor testing circuit (27) comprises motor current detecting circuit (31) and electric moter voltage testing circuit (32); Motor-drive circuit (25) is leaded up to motor current detecting circuit (31) and is outputed signal to parameter controller (26), dynamic compensation target current calculator (30) and fault detection module (24) respectively; Another road outputs signal to dynamic compensation target current calculator (30) and fault detection module (24) respectively by electric moter voltage testing circuit (32).

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