JPH048269B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) This invention relates to a speed-sensitive power steering device, specifically a power steering device that automatically adjusts the magnitude of auxiliary steering force in response to changes in vehicle speed. The present invention relates to a steering feel selection device that allows adjustment characteristics of steering force to be arbitrarily selected. (Prior Art) As this type of speed-sensitive power steering device, the applicant of the present application proposed a device disclosed in Japanese Utility Model Application No. 55-95968.
As shown in FIG. 1, the flow control system includes a variable throttle valve 8 and a fixed throttle valve 9 arranged in parallel between the hydraulic pump 7 and the power steering unit 10, and the control of the variable throttle valve 8 is performed in steps. This is done using motor 6. That is, the flow rate of the pressure fluid discharged from the hydraulic pump 7 is controlled by a variable throttle valve 8 and a fixed throttle valve 9 controlled by a step motor 6 to change the steering force. In the figure, reference numeral 11 denotes a flow rate control valve of the hydraulic pump 7, which causes the excess pressure fluid to flow back to the oil tank 13 when the discharge flow rate of the hydraulic pump 7 becomes excessive. Reference numeral 12 is a pressure relief valve for the power steering unit 10, which causes the excess pressure fluid to flow back to the oil tank 13 when the fluid pressure of the unit 10 becomes excessive. For details, see Jitsukaiaki mentioned above.
Since it is described in the specification of No. 55-95968, the explanation will be omitted here. As shown in FIG. 2, the control device for the step motor 6 detects, for example, the rotational speed of the output shaft of an automobile transmission, and connects the output of a vehicle speed sensor 1, which generates an electric signal that changes in accordance with the vehicle speed, to a one-shot circuit. It is input to an F-V converter (frequency-voltage converter) 2 consisting of a D-A converter (digital-to-analog converter), etc., where it is converted into a voltage proportional to the vehicle speed, and then sent to the Schmitts circuit via a home return circuit 3. Enter group 4. Each Schmitt circuit compares preset voltages V ₁ , V _{2 .} . . Exclusive
A distribution circuit 5 consisting of an OR circuit group, an OR circuit, and an amplifier group receives the output of the Schmitt circuit and determines which of the plurality of excitation coils A, B, and C of the step motor 6 is to be excited. That is, in response to changes in the output of the vehicle speed sensor 1, the step motor 6
The rotation angle of the variable throttle valve 8 is controlled to control the throttle amount of the variable throttle valve 8, and since the details are described in the above specification, a detailed explanation will be omitted. FIG. 3 is a diagram showing an example of a case where the variable throttle valve 8 is formed directly on the rotor shaft 6a of the step motor 6, and the rotor shaft 6a is further provided with a return spring 6.
The rotor shaft 6a is provided with mechanical positioning means such as b, and the rotor shaft 6a is moved to a position where the throttle opening area of the variable throttle valve 8 is minimized by the spring 6b when all of the excitation coils A, B, and C are de-energized. position. When the ignition key switch (not shown) is turned on, the output voltage of the home return circuit 3 rises at a predetermined slope from OV to the maximum voltage, and the control home position is reached where the throttle opening area of the variable throttle valve 8 is maximized. The rotor shaft 6a is rotated. Thereafter, the output voltage of the home return circuit 3 is the value obtained by subtracting the output voltage of the F-V converter 2 from the above maximum value, and the throttle amount of the variable throttle valve 8 is controlled by the control circuit to which this subtracted voltage is applied. Changes are made in stages in response to changes in vehicle speed.
In the figure, 6c is a rotor. In the illustrated case, the step motor 6 is shown mounted directly on the housing of the hydraulic pump 7. (Problems to be Solved by the Invention) Based on the above, the invention of Utility Model Application Publication No. 55-95968 controls the rotation angle of the step motor in response to changes in vehicle speed, and provides steering control when the vehicle is stopped or running at low speed. A system that reduces the force and applies a steering reaction force corresponding to the vehicle speed to the steering wheel shaft when driving at high speeds, thereby eliminating the feeling of uneasiness caused to the driver due to steering wheel wobbling or too light steering resistance, especially when driving at high speeds. It is. However, the appropriate magnitude of the auxiliary steering force determined by the rotation angle of the step motor is not determined only by the vehicle speed. The required magnitude of the auxiliary steering force varies considerably depending on, for example, driving conditions such as differences in road surface resistance, physical strength and habits of the driver, changes in overload, and purpose of use of the vehicle. On the other hand, in the conventional device described above, the relationship between the vehicle speed and the opening amount of the variable throttle valve is always uniquely determined by the voltages V ₁ , V ₂ , . . . V _o preset in the Schmitt circuit group 4. There is. For this reason, the vehicle sales/maintenance company and the driver cannot change this control characteristic later, and there is a problem in that it is not possible to deal with determining factors of the auxiliary steering force other than the vehicle speed mentioned above. (Means for Solving the Problems) In order to solve the above problems, the steering sensation selection device in the speed-sensitive power steering system provided by the present invention includes a pressure fluid conduit that responds to changes in vehicle speed. A control device for a speed-sensitive power steering device that controls a variable throttle valve installed in a vehicle and controls its steering force according to vehicle speed, which uses a microcomputer, and which controls a variable throttle valve installed in a vehicle, and controls its steering force according to the vehicle speed. The mode setting means stores in advance a plurality of types of control characteristics for controlling the opening amount of the variable throttle valve in multiple stages with respect to the vehicle speed, and a changeover switch is connected to the microcomputer. mode selection means for selecting one of the control characteristics; and vehicle speed measurement means for measuring the current vehicle speed by detecting an output pulse signal of the vehicle speed sensor, the vehicle speed sensor being connected to an input port of the microcomputer. and, in accordance with the control characteristic selected by the mode selection means, determine a variable throttle valve and a set opening amount corresponding to the current vehicle speed measured by the vehicle speed measuring means, and determine the current opening amount of the variable throttle valve. and an opening amount control means for determining an opening control amount for the variable throttle valve by comparing the opening amount with the opening amount set for the current vehicle speed in the selected control characteristic. It is a device. (Operation) According to the above means, the control characteristics of the auxiliary steering force with respect to the vehicle speed can be optimized by operating the changeover switch, which is the mode selection means, in accordance with changes in the payload, purpose of use of the vehicle, etc. It can be done. In addition, by using a microcomputer and storing the control characteristics in the memory of the microcomputer, the number of types of control characteristics that can be set in advance can be increased as much as possible, and the reliability and certainty of control can be improved. Plan. The steering force can be adjusted in multiple stages according to the vehicle speed by being equipped with a mode setting means that is made up of a microcomputer's memory and stores in advance control characteristics for controlling the opening amount of the variable throttle valve in multiple stages according to the vehicle speed. The mode setting means stores in advance a plurality of types of control characteristics for controlling the opening amount of the variable throttle valve in multiple stages with respect to the vehicle speed, and the mode selection means selects one of the control characteristics stored in the mode setting means. The mode selection means selects one of the plurality of control characteristics stored in the memory.
The opening amount of the variable throttle valve is adjusted in multiple stages according to the vehicle speed, thereby making it possible to obtain a smooth change in steering force according to the vehicle speed. (Embodiment) The present invention is provided in a speed-sensitive power steering device and operates a selection switch so that control characteristics of auxiliary steering force with respect to vehicle speed are optimized. Therefore, a configuration example using a microcomputer of a speed-sensitive power steering device, which is the premise of the present invention, will be described first. Hydraulic pump 7 and power steering unit 1
0, a variable throttle valve 8 and a fixed throttle valve 9 for controlling the flow rate of the pressure fluid are arranged in parallel, and the rotation angle is controlled based on a pulse signal of a frequency proportional to the vehicle speed from the vehicle speed sensor 1. In a flow control device (see FIGS. 1, 2, and 3) that uses a step motor 6 to control the throttle amount of the variable throttle valve 8 in response to changes in vehicle speed, a vehicle speed sensor 1 and a step motor 6 are connected to each other. In between, as shown in FIG. 4, a microcomputer 14 detects the output pulse signal of the vehicle speed sensor 1, has a CR differentiation circuit 18 connected to its reset terminal, and operates according to a predetermined program; are turned on and off by the output signal of the step motor 6, and each excitation coil A,
A driver circuit 15 including a group of transistors for opening and closing the B, C, and D excitation circuits is provided. Reference numeral 17 designates a switching circuit that receives the output signal from the other output terminal _OB0 of the microcomputer 14 and opens and closes the excitation coils A, B, C, and D of the step motor 6; This is an abnormality indicator connected to output terminal OB ₁ . In addition, the coil terminal voltage of each excitation coil A, B, C, and D is input to each input terminal of the microcomputer 14.
A circuit 19 for reading data into IB ₀ , IB ₁ . . . IB ₃ is provided. The vehicle speed sensor 1 is, for example, the
As disclosed in the invention of No. 1, any device that outputs a pulse signal with a frequency proportional to the vehicle speed may be used as long as it is related to the output shaft of an automobile transmission, a speedometer, or the like. The microcomputer 14 is a one-chip microcomputer, and includes a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and a predetermined number of inputs IA ₀ , INT, IB ₀ ......
IB ₃ , actopt OA ₀ , OA ₁ ...OA ₃ , OB ₀ ,
A general commercial product containing OB ₁ etc. may be used, and the above-mentioned
The programs described below are embedded in the ROM and RAM. The driver circuit 15 consists of a group of transistors connected to each output port OA ₀ , OA _{1 .} . . OA ₃ of the microcomputer 14 . A flowchart of the program stored in the ROM of the microcomputer 14 is shown in Figure 7A, and details of each routine are shown in Figures 7B to 7B.
It is shown in F. The operation will be explained below with reference to FIGS. 4 and 7. When the ignition key switch is turned on, the electronic circuit shown in FIG. A level 1 signal is given. As a result, microcomputer 1
4 output ports OA ₀ , OA ₁ , OA ₂ , OA ₃ ,
OB ₀ and OB ₁ are all turned off and at the same time
Execution of the instruction starts from ROM address 0. In this state, each transistor of the driver circuit 15 of the step motor 6 is in an off state, so the excitation coils A, B, and
No current flows through C and D, so the step motor 6 is operated by the return spring 6 attached to the rotor shaft 6a.
At b, the variable throttle valve 8 in FIG. 1 is stopped at the rotational position where the throttle valve is maximized (minimum throttle opening area). First, an initialization routine is executed.
Here, the RAM in the microcomputer 14
The output port _OB0 is set to logic level 1, and the transistor of the switching circuit 17 is turned on. Next, a routine is executed in which the step motor 6 is rotated to the rotational position where the variable throttle valve 8 shown in FIGS. 1 and 3 is opened to the maximum, that is, to the origin position at which control is started. The details are shown in Figure 7B. At this time, the signals are output from the output ports OA ₀ to _{OA 3} of the microcomputer 14 as shown in Table 1.

[Table] The above table shows an example in which the step motor 6 has 2-2 excitation and 8 steps. Therefore, each transistor of the driver circuit 15 is turned on and off according to Table 1, and the step motor 6 rotates against the return spring 6b attached to the roller shaft 6a, and the variable throttle valve 8 is turned to the maximum value. to the open state. That is, the rotation operation of the step motor toward the control origin shown in FIG. 7B is completed. The step motor drive SUB (subroutine) in the initialization routine in Figure 7B is
It is shown in Figure E. That is, when executing the step motor drive subroutine, it is determined whether the direction of rotation is normal or reverse based on the previous control code. Table 1 shows the case of reversal. Next, the excitation coil end voltage of the step motor 6 is applied to the input port of the microcomputer 14.
IB ₃ , IB ₂ ... are read into IB ₀ , but this means, for example, if 1001 is output from output ports OA ₃ to _{OA 0} and what is read from IB ₃ to IB ₀ is 0110, the micro This is because the connection between the computer 14 and the driver circuit 15, the operation of the driver circuit 15, the coil of the step motor 6, the connection between the battery and the step motor, etc. are determined to be normal. If there is an abnormality, the process moves to the abnormality processing routine shown in FIG. 7A. The processing up to the above is performed at a sufficiently high speed. Since the vehicle is still at a standstill and the variable throttle valve 8 is at its maximum opening, the power steering unit 10 provides maximum steering force assistance. Next, as shown in FIG. 7A, the routine is made interruptible and serves a purpose other than the purpose of the present invention, but this is not always necessary. The output of the vehicle speed sensor 1 is connected to the interrupt terminal (INT) of the microcomputer 14 and the input terminal _IA0 as shown in the fourth diagram. In this example, the microcomputer 14 accepts an interrupt at the rising edge of the pulse signal. Therefore, when a signal from the vehicle speed sensor 1 is input, the process jumps to the interrupt routine at the rising edge of the signal. First, a vehicle speed measurement routine is entered, the details of which are shown in FIG. 7C. The counter V is prepared in the RAM of the microcomputer 14,
First, that area of RAM is cleared to zero. Next, it is checked whether the input terminal _IA0 of the microcomputer 14 to which the output of the vehicle speed sensor 1 is connected is at a logic level of 1 or 0. In this case,
Since the signal from the vehicle speed sensor 1 has just been received, the signal flows in the direction of NO in the figure and 1 is added to the counter V. Subsequently, it is checked whether the counter V is greater than or equal to a specified value. This is to avoid staying in one loop for longer than necessary, and exits from this routine when the value exceeds the specified value. Then, the signal from the vehicle speed sensor 1 is checked again to see if it is 1 or 0, and while the signal is 1, the loop of adding 1 to the counter V is repeated. When the signal from the vehicle speed sensor 1 becomes 0, this routine is exited and the vehicle speed comparison routine is entered. As a result, the counter V
is inversely proportional to the vehicle speed, that is, when the vehicle speed is high, the value of the counter V is small, and when the vehicle speed is low, the value of the counter V is large. It goes without saying that the counter V may be configured to contain a numerical value proportional to the vehicle speed. In the vehicle speed comparison routine, the step motor 6 is controlled to switch the throttle amount of the variable throttle valve 8 each time a predetermined speed is reached in accordance with the steering characteristics. FIG. 7D shows details of the vehicle speed comparison routine. The signal flows in the YES direction when the conditions of each speed comparison step (velocity A or less, B or less, C or less... X or less) is met, and flows in the NO direction when the speed is X or more. Since the routine following each step is the same operation, next we will explain the case where the speed is less than A. First, the fact that the speed is below A is stored in the RAM area, and it is checked whether the current control position of the step motor 6 and the control position that must be controlled when the speed is below A are the same. If they are the same, there is no need to control them again.
Flows in the direction of YES, and counter L (described later) becomes 0.
It is cleared, and then the coil end voltage test subroutine (FIG. 7(e)) is called and executed. This explanation is given in the previous section. Next, if the flow is in the NO direction, a check is made to see if the positional relationship between the current control position of the step motor 6 and the position that must be controlled when the speed is below A is one step of the step motor 6. Ru. In other words, microcomputer 1
Since the control speed of 4 is performed sufficiently fast in response to changes in vehicle speed, it is impossible for the control speed to exceed 2 steps under normal conditions. For example, an abnormality occurs when a change occurs that is considerably faster than a change in vehicle speed, such as when the vehicle speed sensor 1 is damaged while driving or the speedometer's flexible shaft (vehicle speed sensor drive system) is damaged. . Therefore, this step makes it possible to discover abnormal situations,
Appropriate action is taken as described below. In particular, when the abnormal situation occurs during high-speed driving, the conventional system causes the steering wheel to suddenly become lighter, which is dangerous, but this invention completely overcomes this drawback. If this step is successful, then loop counter L is checked. This counter L also
This is prepared in the RAM area and is provided to prevent the step motor 6 from being controlled too quickly. In other words, entering this step means that it is necessary to rotate the step motor 6, but the time interval of entering the speed comparison routine is too short compared to the time during which the vehicle speed changes, and this interval If the vehicle speed is close to the speed at which the variable throttle valve 8 is switched, the step motor 6 will be controlled at shorter intervals than necessary, causing chattering and unstable operation. In order to avoid this, a loop counter L is provided, and the step motor 6 is controlled only when a specified number of consecutive signals come to this step. Therefore, if you have not yet reached the specified number of times,
Add 1 to the counter L, exit from the interrupt routine, and return to the original routine. On the other hand, if the specified number of times is reached, it means that the speed is stable (below speed A), so the counter L is cleared to 0 and the rotation direction of the step motor 6 is set to a predetermined position in the RAM area. Then, the program moves to the step motor drive subroutine, and then exits from the interrupt routine and returns to the original routine. As a result, the step motor 6 is rotated one step. Even after returning to the original routine, when the pulse signal from the vehicle speed sensor 1 is input to the microcomputer 14 again, the interrupt routine is entered again and the above-described steps are executed. If an abnormality occurs in the above operation, the process jumps to an abnormality processing routine. The error handling routine is
It is shown in FIG. In the error handling routine,
First, interrupts are disabled, and even if an interrupt request is made again, it will not jump to the interrupt routine. Next, the step motor 6 is turned off, but this means:
This can be done by setting output ports OA ₀ to _{OA 3} to 0000, which turns off all transistors in the driver circuit 15, but depending on the type of abnormal situation, the transistors in the driver circuit 15 may become conductive and be damaged. Since there is also a transistor in the switching circuit 17,
In other words, a method may be adopted in which the output port OB ₀ is set to 0. These may be selected depending on the design concept of the system. Of course, if the former method is used, the switching circuit 17 is not necessary, and a circuit configuration for direct power supply as shown by the broken line in FIG. 4 may be used. Then, the abnormality display output port OB ₁ is set to 1 and the routine shifts to another routine. As a result, the supply of electrical energy to the step motor 6 is cut off, so that the motor 6 is moved to a position where the variable diaphragm 8 is brought into a state with a small diaphragm opening area by the return spring 6b that biases the rotor shaft 6a. Rotate. Therefore, the steering force assistance of the power steering unit 10 is minimized, completely eliminating the inconvenience that the steering wheel becomes too light when driving at high speed, and safety is dramatically improved. Although the operation in the case where only one vehicle speed sensor 1 is provided has been described above, the vehicle speed sensor 1 may be provided with two vehicle speed sensors 1 and 1' as shown in FIG. The vehicle speed sensors 1 and 1' are installed at the same location or at different locations so as to be able to detect the vehicle speed, and are provided so that the phases of signal generation are shifted from each other. FIG. 8 is a diagram showing the operation when two vehicle speed sensors 1 and 1' are installed as described above, and when either vehicle speed sensor 1 or 1' is turned on, an interrupt is sent to the microcomputer 14. The program then jumps to the interrupt routine, where it is checked whether signals are alternately received from the two vehicle speed sensors 1 and 1'. If they are not alternate, it means that one of the vehicle speed sensors 1 or 1' is damaged, and the process jumps to the abnormality processing routine. It is normal if the signals are input alternately, so if the signal that has just arrived is from a sensor for measurement, it will be executed in the same way as described in the above sections. By providing the two vehicle speed sensors 1 and 1' in this way, it becomes possible to detect damage or malfunction of either of the vehicle speed sensors or the system that reaches the vehicle speed sensor before starting the vehicle. FIG. 6 shows an example in which the rotation sensor 20 is attached directly to the rotor shaft 6a of the step motor 6.
A rotary encoder or other possible means may also be employed. This is provided to check whether the instruction of the rotational position of the step motor 6 is correct. This can be done by reading the output of this rotation sensor 20 into the microcomputer 14 instead of inputting the voltage at the end of the step motor coil in FIG. At this time, step-out of the step motor 6 and mechanical failure can also be detected, compared to the case where the coil end voltage is read. Further, instead of the counting means using the counter L marked with * in FIG. 7D, a hysteresis amount may be provided as in the conventional case. As shown in Fig. 9, this is done by adding a constant to the counter V, determining whether it is greater than the specified value, and if YES, setting the step motor in reverse, and if NO, subtracting the constant from the counter V, If it is below the specified value, the step motor is set to normal rotation. This completes the explanation of the specific example of the speed-sensitive power steering device in which the device of the present invention is incorporated. Next, a configuration example of the present invention will be explained. FIG. 10 shows a mode selection circuit 2 that optimizes the control characteristics of the auxiliary steering force with respect to the vehicle speed.
1. In this figure, an appropriate number of mode selection input terminals IC ₀ , which are pulled up to the microcomputer 14 by resistors R ₀ , R ₁ . . . R _o ,
IC ₁ ... IC _o is provided and some flow characteristics are determined in advance. This flow rate characteristic is a characteristic regarding the relationship between the vehicle speed and the auxiliary steering force, and specifically, a control characteristic of the opening amount of the variable throttle valve with respect to the vehicle speed. Only the types of flow characteristics considered to be necessary for actual vehicle operation are prepared. This setting method is
For example, the memory in the microcomputer 14
This is a ROM, and specifically, it is stored and set as a digital value representing the relationship between the vehicle speed and the rotational position of the step motor. The control characteristics set in this way are arbitrarily selected by the user or end user by operating the selection switches S ₀ , S _{1 ,} . A flowchart at that time is shown in FIG. That is, it may be combined with the vehicle speed comparison routine shown in FIG. 7D. (Effects of the Invention) As detailed above, according to the present invention, various excellent effects as listed below can be obtained. (1) mode setting means for storing in advance a plurality of control characteristics of the opening amount of the variable throttle valve with respect to vehicle speed; mode selection means for selecting one of the control characteristics stored in the mode setting means; and mode selection means for selecting one of the control characteristics stored in the mode setting means; The opening amount of the variable throttle valve is determined by determining a control amount corresponding to the current vehicle speed measured by the vehicle speed measuring means according to the vehicle speed measuring means to be measured and the control characteristics selected by the mode selecting means. Since it is equipped with an opening amount control means for controlling the driving conditions such as differences in road surface resistance,
The control characteristics of the auxiliary steering force relative to the vehicle speed can be arbitrarily selected in accordance with the physical strength and habits of the driver, changes in payload, purpose of use of the vehicle, etc. Therefore, it is extremely beneficial to car sales/maintenance companies and drivers, and can increase the value of the car. (2) Since a microcomputer is used and the mode setting means consists of the memory of the microcomputer, its storage setting capacity is extremely large, and this allows for a wide variety of control characteristics and various steering feels. It becomes extremely easy to obtain the following information, and the reliability and certainty of control is greatly improved. Incidentally, if the mode setting means and the like were constituted only by hardware, the number of parts, especially the changeover switches and the number of wirings would increase, which would lower reliability and increase manufacturing costs. (3) Also, as the above microcomputer,
Since a commercially available product can be used, the cost is low, and since a one-chip type product is sufficient, the installation space is small, and an extremely compact structure can be achieved. (4) Moreover, since the present invention adjusts the opening amount of the variable throttle valve in multiple stages according to the vehicle speed, smooth changes in steering force can be obtained according to the vehicle speed. Further, since the degree of smooth change in steering force can be selected by the mode selection means, the relationship between "vehicle speed and steering force" is arbitrary. This is illustrated in FIG. 12 (this invention) and FIG. 13 (prior art example). Figures 12 and 13 show the adjustable range of the "vehicle speed-steering force" characteristic of the present invention and the conventional example, assuming that the load on the steering system is constant. In the conventional example (Figure 13), the steering force The change is in one step, and the switching point for this vehicle speed is simply switched as shown below. On the other hand, in the present invention (FIG. 12), the steering force can be adjusted in multiple stages according to the vehicle speed, and can be changed like ABC by the functions of the mode selection means, the mode selection means, and the opening amount control means. This provides excellent effects not found in conventional examples.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing the system configuration of a flow rate control device, Fig. 2 is a block circuit diagram showing a conventional step motor control device, Fig. 3 is a partial sectional view showing the configuration of a step motor, and Fig. 4 is a hydraulic circuit diagram showing the system configuration of a flow rate control device. The figure is an electronic circuit diagram of the present invention, FIGS. 5 and 6 are electronic circuit diagrams showing only the main parts of other embodiments, and FIGS.
FIGS. 8 and 9 are flowcharts of other embodiments, respectively, and FIGS.
The figure is an electronic circuit diagram showing only the main parts of another embodiment, FIG. 11 is a flowchart in FIG. 10, and FIG. 12 is a "vehicle speed-steering force" according to this application.
The characteristic diagram, FIG. 13, is a "vehicle speed-steering force" characteristic diagram according to a conventional example. 1, 1'... Vehicle speed sensor, 6... Step motor, 7... Hydraulic pump, 8... Variable throttle, 9...
Fixed aperture, 10...Power steering unit, 14...Microcomputer, 15...Driver circuit, 16...Error indicator, 17...Switching circuit, 18...CR differential circuit, 19...
...Coil end voltage reading circuit, 20...Rotation sensor,
21...Mode selection circuit.

Claims (1)

[Scope of Claims] 1. In a control device for a speed-sensitive power steering device that controls a variable throttle valve provided in a pressure fluid pipe in response to changes in vehicle speed and controls its steering force in accordance with vehicle speed, A mode setting means that uses a microcomputer, and is composed of a memory of the microcomputer and stores in advance a plurality of types of control characteristics for controlling the opening amount of the variable throttle valve in multiple stages with respect to the vehicle speed, and the microcomputer mode selection means for selecting one of the control characteristics stored in the mode setting means; a vehicle speed sensor connected to the input port of the microcomputer; a vehicle speed measuring means for measuring the current vehicle speed by detecting an output pulse signal; and a variable aperture corresponding to the current vehicle speed measured by the vehicle speed measuring means according to the control characteristic selected by the mode selecting means. Determining the set opening amount of the valve and comparing the current opening amount of the variable throttle valve with the set opening amount for the current vehicle speed in the selected control characteristic to determine the opening control amount for the variable throttle valve. 1. A steering feel selection device comprising: an opening amount control means.