JPH04507074A - vehicle control system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] vehicle control system The present invention relates to a vehicle control system, and particularly to a vehicle control system during braking or acceleration. This relates to a control system that controls both.

Several types of vehicle braking systems are known, most of which are It has the disadvantage of causing a phenomenon known as a drop. What is a slip? When braking, the vehicle's wheels rotate at a different speed than the actual road speed. This is a developing system that rotates at low speed. If the amount of slip exceeds a certain limit, The vehicle's wheels lock up, meaning they stop rotating and the driver is unable to maintain full control of the vehicle. It becomes.

A similar phenomenon occurs when a vehicle is rapidly accelerated, but the wheels of the vehicle in this case are It rotates at a higher speed than the rotation speed corresponding to the actual road speed, and this phenomenon is generally “Known as spin °.

From now on, the word "slip" refers to both slip during braking and spin during acceleration. Used inclusively.

There is slippage on each wheel of the vehicle, but it can be detected by detecting the slippage. Anti-lock braking systems intended to reduce this have been proposed in the past. Either If slippage is detected on a wheel, the braking function for that wheel is temporarily reduced. The front is dynamically released and then reactivated. Detection is carried out quickly and repeatedly during braking. However, this system detects if a slip is occurring and takes necessary steps. It is only possible to repeatedly release and restart the brake function. That is, this The system uses brake pedals that affect the degree of slip and/or braking. It is not possible to continuously adjust the braking according to the displacement of the barrel, and it is simply an on-off system. It only operates as a system.

According to the present invention, this vehicle control system uses the actual wheel rotation speed and the actual road running speed. on any wheel of the vehicle by measuring the difference between the rotational speed and the A means of detecting whether a skid has occurred and a means of controlling the vehicle to prevent a detected skid. into control signals to control motion and acceleration, thereby regulating slip. consisting of means.

This control system is used for braking and accelerating the vehicle operated by the driver. and in response to the control signal, apply a force in the opposite direction to the force applied by the driver. and means for adjusting the slip thereby.

Parts operated by the driver include the brake or accelerator pedal. The system includes means for detecting the displacement of the pedal, and the pedal displacement is determined by the slip If a tap is detected, it is converted to provide the control signal.

The means for exerting a force in the opposite direction is a hydraulic actuator ram.

Said means for sensing pedal displacement is an LVDT.

This system determines whether the force applied to the part by the screwdriver exceeds a predetermined value. in the case of the invention, it includes means for releasing said means for exerting a force in the opposite direction.

The release means is a pressure relief valve operative to prevent action of the ram. .

The actual road speed of the vehicle is detected optically, and the rotational speed of the wheels is detected magnetically. be known.

The converting means is a microprocessor.

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of the brake control system of the present invention.

FIG. 2 is a longitudinal sectional view of a hydraulic actuator used in the system of FIG. 1.

FIG. 3 is a graph showing the variables of pedal displacement and slip.

FIG. 4 is a graph showing variables of vehicle traction and slip.

FIG. 11 shows a brake mounted on a piston 9 slidable within the housing 10. 1 is a control system for a vehicle including a key pedal 1. The displacement of brake pedal 1 is Measured by Linear Variable Differential Transformer (LVDT) 2, Linear Variable Differential Transformer (LVDT) 2 converts the mechanical displacement of the piston 9 into an electrical signal, and The number is sent to the microprocessor 5. This brake pedal displacement is other suitable It can also be measured and converted by other means.

Although this diagram depicts a conventional brake pedal, the present invention Applies to any remote control means operated by the driver of a vehicle to Please understand that this can happen.

When the spring 12 is released from pressure, the brake pedal is normally depressed. connected to the brake pedal 1 to ensure that the . The brake pedal 1 is connected to the master cylinder 13 via a linkage 33. It will be done. The linkage 33 is a brake pedal], and a conventional front and rear brake braking system. It acts as an interface between the system and the system.

magnetic sensor 3 (or other suitable means, e.g. optical or Hall effect mounting) detects the rotational speed of each wheel of the vehicle (only one wheel is shown). However, an optical sensor 4 (or other suitable means, e.g. e.g. radar sensor or microunib sensor) Detect speed. The optical sensor 4 is, for example, a retroreflective sensor mounted below the vehicle. It may also be a sensor. The measured wheel rotational speed and vehicle speed are processed by the microprocessor 5. and the microprocessor 5 calculates the actual wheel rotational speed and the actual road running of the vehicle. Each car of the vehicle is determined by measuring the difference between the rotation speed and the row speed. Calculate the degree of slip that has occurred in the ring.

If slippage is detected on one or more wheels, the microprocessor The sensor 5 supplies a control signal derived from the amount of slip and the amount of displacement of the brake pedal 1. , whose control signals are connected to the solenoid valve 7.8, the pressure relief valve 11 and the pressure regulator. Controls a hydraulic system consisting of a regulator 6. This pressure regulator 6 controls the pressure in the system. Any fluctuations in the pressure of the working fluid supplied in order to keep the force substantially constant The working fluid is supplied from a pressure supply P through this pressure regulator 6.

In normal braking conditions, where no slip is detected, the microprocessor 5 These control signals keep valve 7.8 in the closed position (as shown in Figure 1) and release pressure. Valve 11 is biased to the closed position by spring 44 (as shown in FIG. ). If the wheels do not slip in this condition, the displacement of brake pedal 1 is is allowed to proceed without resistance from the control system, and the liquid in the housing 10 passes through the valve 8. Tsute Savings M14! Sent to H.

If slippage is detected on any wheel of the vehicle, the microprocessor 5 Their control signals actuate the valves 7.8 and they move to the open position.

The pressure relief valve 11 releases the pressure in the system at points A and B, and releases the pressure in the system from the spring If the pressure at point B (to which biasing force is applied) of 44 is greater than the pressure at point A, the valve The tab 11 remains in the closed position as shown. Housing through valve 7.8 The hydraulic fluid supplied to the brake pedal 10 provides a resistance force opposite to the displacement of the brake pedal 1. do.

In this way, this control system detects the amount of slip at any wheel. actuates to counteract the force on the brake pedal (supplied by the working fluid of the device). detects the resistance force applied to the brake pedal necessary for control adjustment (supplied by the vehicle) and Optimal level for reducing slippage.

A panic situation occurs and the driver applies force above a certain limit to the brakes. When the pedal is applied, the pressure at point A is the force of the spring 44 and the pressure at point B. , bubble 1] moves to the open position. As a result, inside the housing 10 The liquid flows into the oil storage tank R through valve 1]. In this way, excessive force is prevented from breaking. When applied to the key pedal 1, the pressure release valve 11 is activated and the control system is shut down. It becomes stopped.

Thus, when slip is detected, the control system of the present invention By providing resistance to the operation of the barrel, it is possible to perform continuous operation. Provides more advanced braking modulation (panic) than the simple on/off braking typical of parking systems. It can be seen that the power is supplied (except when the system is closed).

Figure 2 shows the hydraulic actuator used in the system shown in Figure 1. There is. However, the hydraulic actuator in Figure 2 is connected to the brake pedal (not shown). The pressing force applied to the piston 9 is pulled out from the housing 10. It is operated to provide traction for the vehicle.

The piston 9 connects to the brake pedal fulcrum 14 via an actuator rod 35. connected to. As shown in Figure 2, when the brake pedal is depressed, The rake pedal pulls piston 9 from left to right. Fluids of the type shown in Figure 1 The pressure device supplies liquid to a fluid pressure chamber 15 within the housing 10 . piston style The liquid slides inside the sleeve 22 within the body pressure chamber 15, but the liquid 17 prevents the piston from passing from the lower right side to the left hand side (see Figure 2). (Illustrated).

The piston is attached to the moving iron core (slug) 18 of the linear variable differential transformer (LVDT) 2. Connected. Muha iron core 18 is connected to piston 9 and inside the LVDT housing. It becomes possible to slide. The LVDT is the mechanical displacement of the movable core 18, that is, the block It converts the displacement of the rake pedal into an electrical signal that is sent to the microprocessor. Ma Microprocessor is a brake pedal that reduces slip to the optimum level. Determine the required position of the barrel (see Figures 3 and 4 for the optimum slip level). (discussed later in relation to). If slip is detected, fluid will flow to the port (as shown). ) into the cavity 15 and provides resistance to the movement of the piston 9. Ru. Other means equivalent to the LVDT also measure the displacement of the brake pedal and convert the displacement to an electrical source. It will be appreciated that it can be used for converting into air signals.

LVDT2 has mounting 19.20 on both ends and mounting 20 on Yes, so that the LVDT can be removed from the housing 10 if necessary. It has a plug 21 of.

Seals 23, 24 are provided between the sleeve 22 and the housing 10, respectively. and the housing ] 0.

Rubber Gator 25 has dust that enters the hydraulic actuator and affects its function. The end of the piston 9 is covered to prevent it from being exposed.

Housing 10 includes a pressure relief valve 26, which corresponds to valve 11 of FIG.

Valve 26 is moved by tension spring 28 to piston 27 in its normally open position. In that position, the port 34 is closed and the liquid in the valve 26 is drained to the oil storage tank R. Not served.

The valve 26 has a port 37 corresponding to point B in FIG. 1, and a port 37 corresponding to point A in FIG. A working fluid supply (not shown) is connected by a port 36 to a working fluid supply (not shown).

Fluid path 16 leads from 15 to the interior of valve 26 .

The piston 27 is configured such that the pressure supplied through the port 36 is equal to the pressure supplied through the port 37. The closed position is maintained until the biasing force of the spring 28 becomes larger than the biasing force of the spring 28. Then The stone 27 is moved to the open position as shown in FIG. from the cavity 15 into the port 34 through the cavity 15 . Did you do it? I, I feel like I'm in a panic. In this configuration, the pressure relief valve 26 provides a reservoir of hydraulic fluid that opposes movement of the brake pedal. Allowing oil to flow to 11R.

The valve 26 has a seal 29.30.31 that keeps the valve within the housing 10. do.

The hydraulic actuator is connected at one end via a support 14 and at the other end via a support 14. 32, it is fixed to a solid part of the vehicle body in front of the brake pedal.

The fluid pressure actuator is operated by a pressing force while being relaxed.

The control system shown in Figures 1 and 2 includes a vehicle braking system and a progressive brake system. The control system of the present invention reduces vehicle wheel spin. It can also be applied to the accelerator pedal to make gradual acceleration adjustments to . The actual rotational speed of the wheels or less than the rotational speed depending on the actual road speed of the vehicle. When the wheels slip, the actual rotational speed of the wheels is different from the actual rotational speed of the vehicle. A wheel spins when its rotational speed is greater than the speed at which it travels on the road.

In this way, the control system of the present invention can It is clear that the same applies to both pedals.

The control system of the present invention has a tolerable range of wheel slip (as defined herein). It operates on the principle of keeping the

FIG. 3 is a graph showing typical variables of pedal displacement and vehicle slip rate.

This slip ratio is a positive value in a braking state and a negative value in an accelerating state, and is as follows: It is calculated as follows.

In either case, the maximum pedal displacement for a given slip ratio is determined from the graph. It is determined. The slip rate is shown as a percentage of the X-axis-L of the graph.

Various experiments have shown that the optimal slip ratio is between 17% and 20%. ing. However, this value depends to a large extent on road conditions and the tires of the vehicle used. Depends on it. The microprocessor 5 in FIG. 1 is kept within the slip or tolerance range. It is programmed to control the system as follows. X and Y axes of the graph - L The location can be determined by appropriate adjustments to the microprocessor program. It varies depending on the allowable slip range in the situation.

Figure 4 shows the force in the traveling direction (braking or driving force) applied to the vehicle and tire slip. It is a graph showing typical variables of the rate.

In this case, 1. The maximum force in the forward direction that is important during braking or acceleration (braking It can be seen that there is an optimal tire slip ratio that provides the desired amount of driving force (or driving force).

Of course, the slip detection means described here are already used in many vehicles. It can also be integrated into standard ABS braking systems. This vehicle speed degree sensor and wheel speed sensor are currently used to determine if the wheels are locked or It will serve as a substitute for a sensor that only detects something. In that case, the microprocessor is used to apply the brakes to the wheels of a vehicle and release the wheel locks. You will get it.

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Claims (12)

[Claims] 1. The difference between the actual rotational speed of the wheels and the rotational speed according to the actual road speed of the vehicle This system detects whether slipping has occurred on any of the wheels of the vehicle by detecting the and convert the detected slip into a control signal that controls braking or acceleration of the vehicle. and means for converting and adjusting slip. 2. A member operated by the driver to control braking or acceleration of a vehicle and applying a force to the member in a direction opposite to the force exerted by the driver in response to the control signal. 2. The apparatus of claim 1, further comprising means for adjusting slip. 3. The member operated by the driver is a brake or an accelerator pedal. detects the displacement of the pedal, and if slip is detected, supplies the control signal. 3. The apparatus of claim 2, including means for converting pedal displacement to 4. Claim wherein the means for exerting a force in an opposite direction is a hydraulic actuator ram. The device according to scope 3. 5. Claim 3 or 4, wherein the means for detecting the pedal displacement is an LVDT. The device described. 6. When the force applied to said member by the driver exceeds a predetermined value, Claims 2 to 5 include means for releasing the means for exerting a directional force. equipment. 7. The release means is a pressure release valve that operates to prevent the action of the ram. A device as claimed in claim 6 and dependent on claim 4. 8. The actual road speed of the vehicle is detected optically. 7. The device according to 7. 9. The device according to claims 1 to 8, wherein the rotational speed of the wheel is detected magnetically. Place. 10. Claims 1 to 9 above, wherein the converting means is a microprocessor. equipment. 11. A control device for a vehicle substantially as herein described with reference to the drawings. . 12. Control according to claims 1 to 11, operable with respect to each wheel. Vehicle containing equipment.