JPS60226366A - Steering-force controller for electronic control type power steering - Google Patents

Abstract

PURPOSE:To obtain a proper steering force by reading-out an orifice opening- degree control signal from the corresponding region of a memory means on the basis of the output of a plurality of detecting means and driving an actuator. CONSTITUTION:A car-speed signal is input into a microcomputer 15 through a buffer 16, and a steering-angle signal is input through an A/D converter 17. Plural kinds of tables for a memory element 15a are prepared according to the different outside conditions, and the switching to a desired table is performed by a selecting signal through the buffer 16 by the operation from outside. The opening-degree control signal read from the memory element 15a by an access circuit 15b is input into a driving circuit 18, which is driven by the amount proportional to the magnitude of the opening-degree control signal, and an actuator 10a for adjusting the opening-degree of an orifice 10 for varying the steering force is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a steering force control device for an electronically controlled power steering system that can provide an appropriate steering feeling depending on the driving state and steering conditions of a vehicle. Technological method for changing the steering force of power steering,
The input shaft determines the opening degree of the control valve by controlling the flow rate of the liquid flowing into the control valve, and by controlling the equivalent spring constant between the input shaft and the output shaft using the reaction pressure of the hydraulic reaction chamber.・Hydraulic reaction force chamber method that changes the relative displacement of the output shaft and thereby changes the steering force (for example, the
No. 43946) is known, and in both of these, the flow rate and reaction pressure are controlled by changing the opening degree of the oriice in the hydraulic circuit. A linear solenoid, stepping motor, DO servo motor, or the like is used as an actuator for controlling the opening degree of the orifice.

As mentioned above, the steering force of the power steering changes depending on various external factors, so in order to obtain an appropriate steering feeling, the opening of the oriice must be controlled in accordance with those factors to maintain the steering force appropriately. There is a need. The control amount of this orifice is based on loads such as vehicle weight, number of passengers, and loading capacity.
It varies depending on the characteristics of the vehicle, the characteristics of the steering (hydraulic system characteristics, mechanical characteristics), the preferences of the automobile manufacturer, etc. To deal with this, conventionally the circuit constants that determine the relationship between the vehicle speed signal and the orifice control amount and the shape of the orifice have been finely adjusted.

Problems to be Solved by the Invention However, with this approach, manufacturers who supply control devices to consumers must design each control device individually depending on the external factors such as those mentioned above. There are also problems such as increased costs and longer development periods (rework due to tuning work with the vehicle and steering system).

Purpose This invention is capable of obtaining appropriate steering force in response to changes in various external factors such as vehicle running conditions and steering conditions.
It is an object of the present invention to provide a steering force control device for an electronically controlled power steering system that can quickly respond to the above-mentioned external factors in design and standardize the control circuit.

Means for Solving the Problems One of the steering force control devices for electronically controlled power steering according to the present invention is a power steering system that changes the steering force by controlling the opening degree of an orifice in a hydraulic circuit. In a steering force control device for a steering wheel, an actuator drive means for driving the actuator of the orifice, a set of a plurality of external elements related to the steering force, and a specific value given to each element and a corresponding steering force. a storage means for storing a table of the relationship between the opening control amount of the oriice corresponding to the above, a plurality of detection means for detecting the values of the plurality of external elements, and a plurality of detection means for detecting the values of the plurality of external elements; The electronically controlled power steering D steering force control device is characterized in that it comprises an access means for reading an orifice opening degree control signal from a corresponding storage area of a storage means and inputting it to the actuator drive means.

Another aspect of the steering force control device for electronically controlled power steering according to the present invention is to control the equivalent spring constant between the input shaft and the output shaft using the reaction pressure of the hydraulic reaction chamber, and to open the control valve. In a power steering steering force control device that changes the amount of relative displacement between an input shaft and an output shaft that determines the steering angle, thereby changing the steering force, a hydraulic circuit in a hydraulic circuit that supplies pressure fluid to the reaction force chamber is used. An actuator driving means for adjusting and driving the opening degree of the orifice, and a plurality of external elements related to the change in the steering force, at least one of which is a steering angle, as a set, and a specific value given to each element and corresponding thereto. a storage means for storing a table of the relationship between the steering force and the ice opening control amount; a plurality of detection means for detecting the values of the plurality of external elements; A steering angle that samples a steering angle signal output by one of the plurality of detection means for a specific time, takes the average value thereof, and calculates the absolute value of the difference between the steering angle signal from one of the plurality of detection means and the average value. Based on the signal correction means, the output of the detection means corresponding to external factors other than the steering angle, and the output of the steering angle signal correction means, an orifice opening degree control signal is read out from the corresponding storage area of the storage means and is transmitted to the actuator. A steering force control device for power steering according to the present invention has a configuration of a steering force control device for an electronically controlled power steering system characterized by comprising an access means for inputting input to a drive device. No, the values of a plurality of external factors related to changes in steering force are detected by a plurality of detection means, and the plurality of external factors related to a change in steering force are unified based on the outputs of the plurality of detection means. Access is made from the corresponding storage area of the storage means that stores a table of the relationship between the specific value given to each element as a set and the opening control amount of the orifice in the hydraulic pressure circuit corresponding to the corresponding steering force. The orifice opening control signal is read by the means and inputted to the actuator drive means to drive the orifice actuator and control the orifice opening. You can gain power.

Another power steering steering force control device of the present invention has the above-described configuration, and detects the values of a plurality of external elements related to changes in steering force using a plurality of detection means. The steering angle signal correction means samples the steering angle signal outputted by one of the vI number detection means for a specific time, and calculates the average value thereof, and The absolute value of the difference between the steering angle signal and the average value is calculated, and based on the output of the detection means corresponding to external factors other than the steering angle and the output of the steering angle signal correction means, at least one The relationship between the specific value given to each element as a set of multiple external elements where one is the steering angle and the opening control amount of the Oriais in the hydraulic circuit corresponding to the corresponding steering force is tabulated. The access means reads out the orifice opening degree control signal from the corresponding storage area of the stored storage means and inputs it to the actuator driving means to drive the actuator of the orifice and control the opening degree of the orifice. .

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a system diagram of the steering force control device of this embodiment, and the steering gear has a rack cylinder 1, a control valve 2, and a power 7 shift mechanism. The main pump 3 is constantly driven to rotate by the engine 4 via a pulley 5 or the like while the engine 4 is rotating, pressurizes the fluid in the tank 6, and supplies the pressurized fluid to the control valve 2 of the power assist mechanism. The water is then refluxed to tank 6. A sub-pump 7 is constantly driven to rotate by the engine 4 like the main pump 3, pressurizes the fluid in the tank 6, and supplies the pressurized fluid to the hydraulic reaction chamber 8.

The hydraulic reaction chamber 8 receives the supplied pressure fluid and changes the equivalent spring constant between the handle shaft (input shaft) 9 and the steering gear side shaft (output shaft). The control valve 2, whose opening degree is determined by the amount of relative displacement of the shaft, is controlled by the reaction pressure of the hydraulic reaction chamber 8.

Reference numeral 10 denotes an orifice for controlling the reaction pressure of the hydraulic reaction chamber 8, and the opening degree of this orifice 10 is controlled by a control signal output from a control circuit 11.

The power steering force varies depending on external factors such as the driving condition of the vehicle (road curvature, road surface condition, passenger condition, load capacity, vehicle speed, etc.) and steering conditions, so the control circuit described above changes. Actual measured values of a plurality of the external elements are input to 11, and a control signal corresponding to this input is output, thereby controlling the opening degree of the orifice 10. As external factors, vehicle speed and steering angle are selected in this example. 12 is the vehicle speed sensor,
The rotation of the output shaft of the transmission 13 is electrically detected, and the resulting vehicle speed signal is input to the control circuit 11. 1
Reference numeral 4 denotes a steering angle sensor, which is composed of a potentiometer or the like, and detects the steering angle as a voltage signal, for example, by installing the fixed side of the case or the like on a fixed part around the steering wheel, and fixing the sliding side to the steering wheel shaft 9. This steering angle signal is input to the control circuit 11.

FIG. 2 shows a schematic diagram of the configuration of the control circuit 11, and in the figure, 15 is a microcomputer. This microcomputer 15 has a vehicle speed signal, a steering angle signal, and the like. A memory element 15a that stores the relationship between the orifice opening control amount corresponding to the corresponding steering force in a table as shown in FIG. 3, and the memory element that receives the vehicle speed signal and the steering angle signal and corresponds to a combination thereof. An access circuit section 15b is provided to read out the opening degree control signal for the orifice 10 from a predetermined storage area A of the access circuit section 15a. The vehicle speed signal then passes through the buffer 16,
Further, the steering angle signal is input to the microcomputer 15 via the A/D converter 17.

In this embodiment, a plurality of types of tables in the memory element 15a are prepared corresponding to differences in external conditions, and a selection signal is inputted via the buffer 16 by an externally operable selection means. The table can be switched to the desired table by FIG. 4 shows table selection and table data successive output processing in the microcomputer 15 using a diagram 70.

The opening control signal read out from the storage element 15a by the access circuit section 15b is input to the drive circuit 18, and the drive circuit 18 is driven by an amount proportional to the magnitude of the opening control signal to open the orifice 10. The actuator 10a that adjusts the opening degree is activated. The opening degree control signal is a signal corresponding to the number of steps if the actuator 10a is a stepping motor, or a current value if the actuator 10a is a stepping motor.

. . Embodiment A is based on the steering force, related elements, A, and (
The vehicle speed and steering angle are then selected, and these values and the orifice opening control amount are created in a table. Of course it's a good thing.

5 to 7 show another embodiment of the invention, and since the overall system of the steering force control device is the same as that shown in FIG. 1, the description thereof will be omitted here.

The same reference numerals as in FIG. 1 are used to describe the same parts in the following description.

FIG. 5 is a block diagram showing a schematic configuration of the control circuit 11 that outputs the opening degree control signal of the orifice 10. Therefore, the memory element 15a of the microcomputer 15 stores the vehicle speed signal and the steering control signal as shown in FIG. The relationship between each angle signal and the orifice opening control amount corresponding to the corresponding steering force is stored in a table form.

The processing in the microcomputer 15 is shown in FIG. 6(a).
The process is carried out as shown in the flowchart shown in l (1:+).

The steering center, which corresponds to when the vehicle is traveling straight, does not necessarily correspond to the zero position of the actual steering angle, and may vary depending on various driving conditions (road curvature, road surface conditions, occupant conditions). , loading capacity, vehicle speed, etc.), the program of the microcomputer 15 calculates the absolute value of the difference between the input steering angles as shown in FIG. 6(b), and calculates the steering angle corrected in this way. The corresponding storage area of the storage element 15a is accessed based on the signal θ.

The above-mentioned calculation of the statistical average value θ of the steering angle signal is not carried out all the time, but is carried out only during a specific period when the inputted steering angle signal θt is in the region shown in the table of FIG. When a vehicle is running, the steering angle becomes smaller as the vehicle speed increases. Therefore, in the above table, the area shown in the figure is set to decrease as the vehicle speed increases.

In addition, in the calculation of the above-mentioned steering angle signal, an upper limit value θ2 and a lower limit value θl are set for the statistical average value j, and when the result of the calculation exceeds the upper limit value θ2, the average value j is set to 02, and Lower limit value θ1f: When lower, set the average value θ to 01
It is made to be.

The orifice opening control signal read from the memory element 15 & is input to the drive circuit 18 as in the previous embodiment of the invention, and the drive circuit 18 is driven by an amount proportional to the magnitude of this opening control signal. The actuator 10a is driven to adjust the opening degree of the orifice IO.

It goes without saying that the calculation of the statistical average value j is not limited to the above example, and may be performed using other calculation methods.

Effects of the Invention One of the steering force control devices for electronically controlled power steering according to the present invention is capable of controlling the performance of a vehicle by replacing the storage means with a table TL, or by preparing a plurality of types of tables and selecting one of them. Designs that respond to changes in various external factors such as driving conditions and steering conditions can be quickly implemented, making it possible to standardize control circuits, thereby reducing costs and shortening the development period.

Further, another one of the steering force control devices for electronically controlled power steering according to the present invention not only provides the same effects as the above-mentioned invention, but also has the steering angle signal correcting means, so that when the vehicle is traveling straight, This makes it possible to detect the steering angle that corresponds to the steering angle, which has the effect of being able to obtain a steering force that correctly corresponds to the steering angle in accordance with various driving conditions.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is a block diagram of its control circuit, FIG. 3 is a diagram showing a two-dimensional example of a table stored in a memory element, and FIG. Figure 5 is a flow diagram showing the control logic of the microcomputer, Figure 5 is a block diagram of a control circuit according to another embodiment of the invention, and Figures 6(a) and (b) show the control logic of the microcomputer. FIG. 7 is a diagram showing a two-dimensional example of a table stored in a memory element.

Claims (2)

[Claims] (1) The steering force is changed by controlling the opening degree of the orifice in the hydraulic circuit. <In the steering force control device for power steering, an actuator drive means for driving the actuator of the orifice, and a set of a plurality of external elements related to changes in the steering force, and specific values given to each element and the storage means for storing a table of the relationship between the opening control amount of the orifice corresponding to the corresponding steering force; a plurality of detection means for detecting the values of the plurality of external elements; A steering force control device for an electronically controlled power steering system, comprising access means for reading out a georifice opening control signal from a corresponding storage area of the storage means based on the output and inputting the signal to the actuator drive means. (2) controlling the equivalent spring constant between the input shaft and the output shaft with the reaction pressure of the hydraulic reaction chamber to change the amount of relative displacement between the input shaft and the output shaft that determines the opening degree of the control valve; In the steering force control device for power steering, which changes the steering force according to the above, the actuator driving means drives to adjust the opening degree of an orifice in a hydraulic circuit that supplies pressure fluid to the reaction force chamber; A relationship between a specific value given to each element as a set of a plurality of external elements related to changes in force and at least one of which is the steering angle, and the opening control touch of the oriice corresponding to the corresponding steering force. a storage means for storing the values in a table, a plurality of detection means for detecting the values of the plurality of external elements, and one of the plurality of detection means.
Steering angle signal correction that samples the steering angle signal outputted by the sensor for a specific period of time, calculates the average value thereof, and calculates the absolute value of the difference between the steering angle signal from one of the plurality of detection means and the average value. Based on the output of the detection means corresponding to external factors other than the steering angle and the output of the steering angle signal correction means, a georift opening control signal is read out from the corresponding storage area of the storage means and is used to drive the actuator drive means. A steering force control device for electronically controlled power steering, characterized in that it is equipped with an access means for inputting information to the