Automobile steering control circuit and automobile

Abstract

The utility model relates to an automobile steering control circuit and an automobile. The automobile steering control circuit comprises at least one motor and at least two steering rheostats connected with the motor. The motion trail of the sliding contact of the steering rheostat satisfies a non-circular curve, and the non-circular curve satisfies an equation (1): r (alpha) = d / (2 + c * sin (2 alpha) + c2sin2 (alpha)) or an equivalent equation of the equation (1). The steering rheostat is used for converting the automobile steering angle into the resistance value of the sliding contact end and then converting the resistance value of the sliding contact end into a voltage signal according to the resistance voltage dividing principle. The resistance value of the steering rheostat is in positive correlation with the sliding arc length of the sliding contact. The motor is used for driving corresponding wheels of the automobile to steer according to the potential difference of the sliding contact ends of the at least two steering rheostats. The device can avoid the constraint of an Akammann steering trapezoidal connecting rod in the prior art, and has the advantages of simple structure, convenience in steering, high flexibility, high reliability and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of automobiles, in particular to an automobile steering control circuit and an automobile. Background Art

[0002] For car steering, the steering angles of the inner and outer wheels are in a nonlinear relationship. The core of the current traditional car steering solution is inseparable from the Ackman steering trapezoid. For increasingly intelligent electric vehicles, the Ackman steering trapezoid has several shortcomings: the maximum steering angle is limited; it cannot strictly meet the Ackman formula; it cannot achieve special motion modes such as rotation, and cannot give full play to the advantages of electric vehicles; if the program control solution is fully adopted, there will be reliability risks, especially under complex road conditions, and the requirements for real-time signal acquisition and analysis are extremely high. The program control solution cannot meet actual needs well. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a vehicle steering control circuit and a vehicle.

[0004] The technical solution adopted by the utility model to solve the technical problem is: an automobile steering control circuit, comprising at least one motor and at least two steering rheostats connected to the motor;

[0005] The motion trajectory of the sliding contact of the steering resistor satisfies a non-circular curve, and the non-circular curve satisfies equation (I): (r(α)=d / (2+c*sin(2α)+c 2 sin 2 (α)) or an equivalent equation of equation (I);

[0006] Among them, r is the polar diameter; α is the polar angle; c is a constant related to the ratio of the wheelbase to the wheelbase of the car, which is related to the shape of the steering resistor; d is the center distance between the two non-circular curves, which is related to the size of the steering resistor;

[0007] The steering rheostat is used to convert the steering angle of the car into the resistance value of the sliding contact end, and then convert the resistance value of the sliding contact end into a voltage signal according to the resistance voltage division principle; wherein the resistance value of the steering rheostat is positively correlated with the arc length of the sliding contact;

[0008] The motor is used to drive the corresponding wheels of the vehicle to steer according to the potential difference between the sliding contact ends of at least two steering rheostats.

[0009] In one embodiment, the sliding rheostat comprises a sliding contact, a breakpoint and a body, wherein the body is an insulating core having a shape conforming to the non-circular curve, and a resistance wire is wound around the insulating core; or, the body is a resistor sheet having a shape conforming to the non-circular curve;

[0010] The breakpoint is set near the polar angle of 180°, with the polar angle of 0° in the polar coordinate system as the starting point, the area above the starting point is the inner resistor end, and the area below the starting point is the outer resistor end;

[0011] The sliding contact is one of a sliding sheet, a resistance wire or a resistance sheet.

[0012] In one embodiment, the motor includes a first motor, the control circuit includes a conjugate symmetrical steering rheostat R1 and a steering rheostat R2, the left front wheel of the vehicle rotates synchronously with the steering rheostat R1, and the right front wheel of the vehicle rotates synchronously with the steering rheostat R2;

[0013] The outer resistance end of the steering rheostat R1 is connected to the positive pole of the power supply, and its sliding contact moves to the inner resistance end when it turns left;

[0014] The inner resistance end of the steering rheostat R2 is connected to the positive pole of the power supply, and its sliding contact moves toward the outer resistance end when it turns left;

[0015] The first motor is used to drive the right front wheel to steer when the potential difference between the sliding contact ends of the steering rheostat R1 and the steering rheostat R2 exceeds a preset deviation range, and drives the sliding contact of the steering rheostat R2 to rotate until the potential difference is within the preset deviation range, and then stops driving.

[0016] In one embodiment, the first motor is used for:

[0017] When the steering wheel turns left, the sliding contact of the steering rheostat R1 turns left accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn left to eliminate the potential deviation;

[0018] When the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn right to eliminate the potential deviation.

[0019] In one embodiment, the control circuit includes a reversing switch S1 connected to the steering rheostat R1 and the steering rheostat R2, the forward gear of the reversing switch S1 is used to make the steering rheostat R1 and the steering rheostat R2 conjugate symmetrical; the reverse gear of the reversing switch S1 is used to make the steering rheostat R1 and the steering rheostat R2 mirror symmetrical;

[0020] When the reversing switch S1 is connected to the reverse gear, the inner resistance end of the steering rheostat R1 is connected to the positive electrode of the power supply, and its sliding contact moves to the inner resistance end when it turns left, and the inner resistance end of the steering rheostat R2 is connected to the positive electrode of the power supply, and its sliding contact moves to the outer resistance end when it turns left;

[0021] At this time, the first motor is used for:

[0022] When the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn left to eliminate the potential deviation, and the angle at which the left front wheel turns right is the same as the angle at which the right front wheel turns left.

[0023] In one embodiment, the motor includes a second motor and a third motor, the control circuit also includes a steering rheostat R3, a steering rheostat R4 and a mode control switch S2, the left rear wheel of the car rotates synchronously with the steering rheostat R3, and the right rear wheel of the car rotates synchronously with the steering rheostat R4;

[0024] The mode control switch S2 is used to control the steering rheostat R3 and the steering rheostat R4 to connect to or disconnect the power supply;

[0025] The second motor is used for:

[0026] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns right, and accordingly, the sliding contact of the steering rheostat R1 turns right, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and when the potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn left to eliminate the potential deviation, and the left turning angle of the sliding contact of the steering rheostat R3 is the same as the left turning angle of the sliding contact of the steering rheostat R2;

[0027] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns left, and accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U3 of the steering rheostat R3, and when the potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn right to eliminate the potential deviation, and the right turning angle of the sliding contact of the steering rheostat R3 is the same as the right turning angle of the sliding contact of the steering rheostat R2;

[0028] The third motor is used for:

[0029] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns right, and accordingly, the sliding contact of the steering rheostat R1 turns right, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U4 of the steering rheostat R4, and when the potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn right to eliminate the potential deviation, and the right turning angle of the sliding contact of the steering rheostat R4 is the same as the right turning angle of the sliding contact of the steering rheostat R1;

[0030] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, and the steering wheel turns left, accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U4 of the steering rheostat R4, and when the potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn left to eliminate the potential deviation, and the left turning angle of the sliding contact of the steering rheostat R4 is the same as the left turning angle of the sliding contact of the steering rheostat R1.

[0031] In one embodiment, the motor includes a fourth motor, and the control circuit further includes a steering resistor R5 and a steering resistor R6 which are coaxially reversed and connected in series;

[0032] Among them, the steering resistor R5 forms a conjugate pair with the steering resistor R1, and the steering resistor R6 forms a conjugate pair with the steering resistor R2; when the sliding contact of one of the steering resistor R5 and the steering resistor R6 enters the inner resistance end, the sliding contact of the other one enters the outer resistance end synchronously, and the rotation angles are equal;

[0033] The fourth motor is used to drive the steering rheostat R5 and the steering rheostat R6 to steer, so that the four wheels satisfy the Ackerman formula, thereby realizing a four-wheel turning mode.

[0034] In one embodiment, the control circuit further includes a control switch 31, a control switch S32, a control switch S33 and a reversing switch S34;

[0035] The control switch S31 is connected between the power supply and the steering resistor R5 and the steering resistor R6, and is used to connect or disconnect the steering resistor R5 and the steering resistor R6;

[0036] The control switch S32 is connected to the first motor, the steering rheostat R1, and the steering rheostat R6, and is used to switch the potential reference signal for driving the right front wheel to steer between the sliding contact potential U1 and the sliding contact potential U6 of the steering rheostat R6;

[0037] The control switch S33 is connected to the third motor, the steering rheostat R1, and the steering rheostat R2, and is used to switch the potential reference signal for driving the right rear wheel to steer between the sliding contact potential U1 and the sliding contact potential U2;

[0038] The reversing switch S34 is connected to the second motor, the steering rheostat R1, and the steering rheostat R3. The forward gear of the reversing switch S34 is used to drive the second motor to turn the left rear wheel left when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range; the reverse gear of the reversing switch S34 is used to drive the second motor to turn the left rear wheel right when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range;

[0039] The fourth motor is used for:

[0040] When the reversing switch S1 is connected to the forward gear, the mode control switch S2 is closed, the control switch S31 is closed, the control switch S32 is connected to the sliding contact potential U6, the control switch S33 is connected to the sliding contact potential U2, the reversing switch S34 is connected to the reverse gear, the steering wheel turns left, and accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U5 of the steering rheostat R5, and when the potential deviation exceeds the preset deviation range, the steering rheostat R5 and the steering rheostat R6 are driven to turn left to reduce the sliding contact potential U6, thereby realizing the four-wheel turning mode.

[0041] In one embodiment, the control circuit further comprises at least one differential amplifier, wherein two input terminals of the differential amplifier are correspondingly connected to sliding contact terminals of two steering resistors, and an output terminal of the differential amplifier is connected to the motor, and each motor corresponds to one differential amplifier; or

[0042] The control circuit further comprises at least one voltage comparator, two input terminals of the voltage comparator are correspondingly connected to the sliding contact terminals of the two steering resistors, and the output terminal of the voltage comparator is connected to the motor to control the power relay switch of the motor; or

[0043] The control circuit also includes a digital circuit module, the input end of the digital circuit module is connected to the sliding contact ends of two steering resistors, the output end of the digital circuit module is connected to the motor, and the digital circuit module is used to digitize the potential difference to drive the motor to turn in a corresponding direction.

[0044] In addition, the utility model also provides a car, comprising the car steering control circuit as described above.

[0045] The automobile steering control circuit and automobile implementing the utility model have the following beneficial effects: by converting the relationship that the angle satisfies the Ackerman formula into a voltage balance relationship between two variable resistor sliding contacts to drive the wheel steering, the constraints of the Ackerman steering trapezoidal connecting rod in the prior art can be avoided, and the utility model has the advantages of simple structure, convenient steering, strong flexibility, high reliability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0047] Figure 1 This is a schematic diagram of the structure of a vehicle steering control circuit according to an embodiment of the utility model;

[0048] Figure 2 It is a schematic diagram of the structure of the automobile steering control circuit of some embodiments of the utility model;

[0049] Figure 3 It is a schematic diagram of the structure of the automobile steering control circuit of some embodiments of the utility model;

[0050] Figure 4 It is a schematic diagram of the structure of the automobile steering control circuit of some embodiments of the utility model;

[0051] Figure 5 It is a mathematical analysis schematic diagram of the motion trajectory of the sliding contact of the steering rheostat of the utility model;

[0052] Figure 6 is a schematic diagram of a model of a steering resistor in some embodiments of the utility model;

[0053] Figure 7 is a schematic diagram of a model of a steering resistor in some embodiments of the utility model;

[0054] Figure 8 yes Figure 7 A top view of the steering rheostat shown;

[0055] Fig. 9 is a top view of the coaxial series connection of steering resistors in some embodiments of the utility model;

[0056] Fig.10 yes Fig. 9 The steering rheostat shown is a coaxial series axial diagram;

[0057] Fig.11 yes Fig. 9 The left side view of the coaxial series connection of the steering rheostat core shown;

[0058] Fig.12 It is a schematic diagram of the relationship between the four-wheel turning angles;

[0059] Fig.13 It is a schematic diagram of the steering angle and wheel movement direction in the forward swing mode;

[0060] Fig.14 is a schematic diagram of the steering angle and wheel movement direction in rotation mode;

[0061] Fig.15 It is a schematic diagram of the steering angle and wheel movement direction in the lateral mode;

[0062] Fig.16 It is a schematic diagram of the steering angle and wheel movement direction in the four-wheel turning mode;

[0063] Fig.17 This is a comparison diagram of the wheel movement direction angles of the utility model and the prior art. DETAILED DESCRIPTION

[0064] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0065] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0066] It should be understood that although the words "first", "second" and the like may be used to limit components in the embodiments of the present utility model, this is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of the present application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0068] It should be noted that the elimination of potential deviation in the present invention does not only mean to completely make the potential deviation zero, but more generally means to make the potential deviation within the allowable range of deviation or within the allowable range of error accuracy. When designing the actual circuit, it is necessary to take into account both power consumption and sensitivity requirements. The deviation requirement of the steering angle does not belong to high-precision requirements, so there is no need to have excessively high sensitivity requirements, and a suitable working voltage (power supply) can be used according to actual needs.

[0069] The automobile in one embodiment of the utility model comprises a vehicle frame, and a steering wheel, a front left wheel, a front right wheel, a rear left wheel, a rear right wheel, a vehicle steering control circuit, etc., which are installed on the vehicle frame.

[0070] Combination Figures 1 to 5 The automobile steering control circuit includes at least one motor and at least two steering resistors connected to the motor.

[0071] The motion trajectory of the sliding contact of the steering resistor satisfies the non-circular curve, and the non-circular curve satisfies equation (I): (r(α)=d / (2+c*sin(2α)+c 2 sin 2 (α)) or an equivalent equation of equation (I).

[0072] Where r is the polar diameter. α is the polar angle. c is a constant related to the ratio of the wheelbase to the wheelbase of the car, which is related to the shape of the steering rheostat. d is the center distance between the two non-circular curves, which is related to the size of the steering rheostat.

[0073] The steering rheostat is used to convert the steering angle of the car into the resistance value of the sliding contact end, and then convert the resistance value of the sliding contact end into a voltage signal according to the resistance voltage division principle. Among them, the resistance value of the steering rheostat is positively correlated with the arc length of the sliding contact.

[0074] The motor is used to drive the corresponding wheels of the vehicle to steer according to the potential difference between the sliding contact ends of at least two steering rheostats.

[0075] like Figure 5 As shown in the figure, a set of conjugate non-circular curves can be derived according to the pure rolling characteristics of the curves and the requirements of the Ackerman formula to meet the requirements. The derivation process is as follows:

[0076] Let d0 be the center distance between the two conjugate curves

[0077] Let the equation of the left curve be: r1(α)

[0078] The equation of the curve on the right is: r2(β)=d0-r1(α) (1)

[0079] Ackerman formula: ctg(α)+a / b=ctg(β); (2)

[0080] Among them, a is the track (actually the distance between the steering axes of the left and right front wheels), and b is the wheelbase.

[0081] The arc length formula satisfies: ds1 2 =dr1 2 +(r1dα) 2 =ds2 2 =dr2 2 +(r2dβ) 2 ; (3)

[0082] According to formula (1), we can get: dr1 = -dr2; according to formula (3), we can get: r1dα = r2dβ;

[0083] Note: The solution of r1dα=-r2dβ does not meet the design requirements.

[0084] That is, r1 / (d0-r1)=dβ / dα (4)

[0085] From (2), we can get: dβ / dα=1 / (1+a / b*sin(2α)+(a / b) 2 sin 2 (α)); (5)

[0086] From (4), we can deduce that: r1(α)=d0 / (2+a / b*sin(2α)+(a / b) 2 sin 2 (α)

[0087] At the same time, we get: r2(β)=d0-r1(α)=d0 / (2-a / b*sin(2β)+(a / b) 2 sin 2 (β))

[0088] Obviously, when α=-β, r1(α)=r2(β)=r1(π+α), that is, the two conjugate curves are congruent and the curves are self-conjugate.

[0089] According to the above derivation process, when the conjugate curves roll purely against each other, the angle satisfies the Ackerman formula, and the change in arc length is always equal. Based on this feature, a variable resistor is designed using the curve so that the trajectory of the variable resistor sliding contact satisfies the curve. By using the characteristic that the resistance value is proportional to the arc length, it is obvious that the angle can be converted into the resistance value, and the angle can be converted into a voltage signal by using the resistor voltage division principle in the circuit. By using a pair of the same type of variable resistors, the relationship that the angle satisfies the Ackerman formula can be converted into a voltage balance relationship between the two variable resistor sliding contacts, and then the voltage signal can be used to achieve real-time control of the steering.

[0090] This embodiment uses a special steering rheostat, and the movement trajectory of the sliding contact of the steering rheostat conforms to a specific curve equation (r(α)=d / (2+c*sin(2α)+c 2 sin 2 (α)), the rotation angle of the sliding contact of the steering resistor is always synchronized with the rotation angle of the corresponding wheel.

[0091] In the equation, the variable r is the polar diameter, α is the polar angle, that is, the wheel rotation angle, and the constant c is the characteristic parameter, which determines the shape of the curve, that is, the shape of the rheostat, and is related to the ratio of the car's wheelbase to the wheelbase. The constant d determines the size of the curve shape, which also determines the size of the rheostat.

[0092] According to the above formula, it is easy to deduce that when the ratio of the rotation angle of the sliding contact of the steering rheostat to the rotation angle of the wheel is not 1:1, assuming it is n:1, the curve equation is r(α)=d / (2+c*sin(2α / n)+c 2 sin 2 (α / n). α is the rotation angle of the rheostat, and α / n is the actual wheel steering angle. According to the periodic characteristics of the curve and the requirements of avoiding crossing and practical transmission, it is easy to get n=2 / k, where k is a positive integer; considering the maximum wheel steering angle, it is recommended that the maximum steering angle be allowed to be 90°. Considering the breakpoint requirements, the recommended range of the actual steering angle of the rheostat is (-180°, 180°), that is, the n value should be less than 2, that is, n<=1, that is, k>=2. Therefore, from the perspective of actual production and installation, n=1 (that is, k=2) is recommended. This article uses n=1 to design and explain the solution.

[0093] Each wheel corresponds to a steering rheostat, and a mechanical transmission method is used to ensure that the wheel rotation angle is synchronized with the rotation angle of the rheostat sliding contact. In this way, the steering angle of each wheel can be converted into a potential signal. The potential difference between the left and right front wheels depends on the steering angle of the left and right front wheels. When the steering angles of the two satisfy the Ackerman formula, a balanced circuit is formed, and the potential difference is 0. Once an angle deviation occurs, a corresponding voltage difference signal will appear.

[0094] The control circuit also includes at least one differential amplifier, the two input ends of the differential amplifier are correspondingly connected to the sliding contact ends of the two steering resistors, the output end of the differential amplifier is connected to the motor, and each motor has a corresponding differential amplifier. Alternatively, the control circuit also includes at least one voltage comparator, the two input ends of the voltage comparator are correspondingly connected to the sliding contact ends of the two steering resistors, and the output end of the voltage comparator is connected to the motor to control the power relay switch of the motor. Alternatively, the control circuit also includes a digital circuit module, the input end of the digital circuit module is connected to the sliding contact ends of the two steering resistors, the output end of the digital circuit module is connected to the motor, and the digital circuit module is used to digitize the potential difference to drive the motor to the corresponding direction.

[0095] That is to say, according to the accuracy requirements, a suitable amplifier circuit (such as a differential amplifier) ​​can be used to amplify the voltage difference signal, which can be used for the DC servo motor to drive the passive wheel to steer. The voltage difference can also be digitized, that is, it is also feasible to control the motor using a digital circuit. Alternatively, using a voltage comparator to control the relay switch of the power supply of the steering motor is also a feasible solution. The utility model uses a simple DC amplifier to drive a DC servo motor to illustrate the principle of the solution.

[0096] After the potential difference appears, the servo motor drives the wheel to turn to a certain angle. When the Ackerman formula is satisfied, the potential difference drops to 0, and the steering servo motor stops turning. This embodiment uses a simple differential amplifier for schematic diagram. In actual application, an operational amplifier can be selected to drive the motor according to needs, or a voltage comparator can be used to control the servo motor power switch or the pulse signal of the stepper motor to drive the wheel to turn correctly.

[0097] like Figures 6 to 8 The figure shows a schematic diagram of a sliding resistor model. The sliding resistor includes a sliding contact, a breakpoint and a body. The body is an insulating core whose shape conforms to a non-circular curve, and a resistance wire is wound on the insulating core. Alternatively, the body is a resistor sheet whose shape conforms to a non-circular curve.

[0098] The breakpoint is set near the polar angle of 180°, with the polar angle of 0° in the polar coordinate system as the starting point, the inner resistor end is above the starting point, and the outer resistor end is below the starting point.

[0099] The sliding contact is a slider, a resistance wire or a resistance sheet, etc.

[0100] In some embodiments, such as Figure 6 As shown, the resistance wire is wound on an insulating core that conforms to the equation curve, and the insulating core is manufactured according to the equation curve.

[0101] In some embodiments, such as Figure 7 and Figure 8As shown, the resistor is made according to the curve. The breakpoint is close to the polar angle of 180°. The insulating material is also used to make a frame to support the resistor according to the curve to form a steering rheostat that meets the requirements. The sliding contact can be either a slider or a resistor wire or a resistor. It only needs to move the slider and the resistor wire or resistor relative to each other along the curve equation. The starting point is the point where the polar angle is 0 in the polar coordinate system. It is necessary to design a physical mark on the rheostat to facilitate the slider to return to 0 and installation. Because the moving trajectory of the sliding contact point of the rheostat just conforms to the curve equation, it is obvious that the resistance value is proportional to the arc length. When two rheostats of the same type are connected to the circuit in the form of a conjugate pair, that is, they are connected to the circuit in opposite directions, the voltage difference is 0 when the rotation angle conforms to the Ackerman formula. When the two rheostats are connected to the circuit in the same direction, the rotation angle is the same, and the voltage difference is 0 when the rotation direction is opposite. Considering that the outer steering angle of the special mode movement is large but does not exceed 90°, it is recommended that the effective resistance area meets the outer steering angle of 90° and the inner steering angle meets cot(α)+a / b=0 in actual design. In the actual solution, it is recommended to design a zero calibration device. By adjusting the contacts at both ends, the initial position of the sliding contact point must be ensured to be at the middle point, that is, the voltage is 0 when the contact point is at (d / 2,0).

[0102] According to the theoretical derivation process, the X-axis is the dividing point, and the upper and lower areas are the inner and outer steering resistance areas respectively. According to the theoretical derivation process in the previous article, it can be known that when the inner and outer steering angles match the Ackerman formula, the arc lengths are equal, so the resistance values ​​are the same. Therefore, a suitable circuit can be designed to convert the angle deviation into the resistance deviation, and finally form a voltage difference as the control signal.

[0103] Specifically, in the automobile steering control circuit of the utility model, there are two key points in the use of the steering rheostat. One is whether the positive voltage is connected to the inner resistor end (inner end) or the outer resistor end (outer end) when connected to the circuit; the other is the mechanical transmission relationship with the wheel, that is, when the wheel turns left, the sliding contact of the rheostat moves to the inner end or the outer end. Therefore, there are four connection states, which are marked in the figure as follows: positive voltage connected to the inner end - inner positive; positive voltage connected to the outer end - outer positive; left turn to move the inner end - left inner; left turn to move the outer end - left outer. The connection method of the steering rheostat in the circuit diagram is explained in this simplified marking in the following text. The connection method of the two rheostats is conjugate when the voltages are opposite and the directions are opposite; the voltage is the same and the directions are opposite, which is mirror symmetry.

[0104] like Figure 1As shown, it is a schematic diagram of the principle of the basic steering control circuit, the motor includes a first motor M1, the control circuit includes a conjugate symmetrical steering rheostat R1 and a steering rheostat R2, the left front wheel of the car rotates synchronously with the steering rheostat R1, and the right front wheel of the car rotates synchronously with the steering rheostat R2. The protection resistor R01 is connected between the positive electrode of the power supply and the first connection terminals of the two steering rheostats, and the protection resistor R02 is connected between the negative electrode of the power supply and the second connection terminal of the steering rheostat.

[0105] The outer resistance end of the steering rheostat R1 is connected to the positive pole of the power supply, and its sliding contact moves to the inner resistance end when it turns left. The inner resistance end of the steering rheostat R2 is connected to the positive pole of the power supply, and its sliding contact moves to the outer resistance end when it turns left.

[0106] The first motor M1 is used to drive the right front wheel to steer when the potential difference between the sliding contact ends of the steering rheostat R1 and the steering rheostat R2 exceeds a preset deviation range, and drives the sliding contact of the steering rheostat R2 to rotate until the potential difference is within the preset deviation range and the driving is stopped.

[0107] Specifically, the first motor M1 is used for: when the steering wheel turns left, the sliding contact of the steering resistor R1 turns left accordingly, so that the sliding contact potential U1 of the steering resistor R1 is less than the sliding contact potential U2 of the steering resistor R2, and when its potential deviation exceeds the preset deviation range, it drives the right front wheel to turn left, and at the same time drives the sliding contact of the steering resistor R2 to turn left to eliminate the potential deviation.

[0108] When the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn right to eliminate the potential deviation.

[0109] When the sliding contact potential U1 of the steering resistor R1 is equal to the sliding contact potential U2 of the steering resistor R2, or the potential deviation thereof is within a preset deviation range, the wheels are not driven to rotate.

[0110] The maximum values ​​of the two conjugate symmetrical steering resistors are both R max , the connection method of the steering resistor is: R1 is the connection method of external positive left inside; R2 is the connection method of internal positive left outside; the driving signal of the amplifier is the voltage difference U1-U2 at the sliding contact end of the two resistors; Figure 1 In, R 1R and R 2R are the resistances from the steering rheostat contact to the positive voltage terminal respectively; the potential difference formula is:

[0111]

[0112] In the formula, the ratio of the resistance difference to the maximum value reflects the sensitivity.

[0113] Assume that the allowable steering angle deviation is 0.5°. Estimated by an arc, it is equivalent to accurately judging a 0.5° difference in the length of the semi-circular arc, and the relative accuracy is about 3%. When the voltage difference signal is below 0.06V0, it can be used as the judgment of the equilibrium state;

[0114] That is to say, in this embodiment, increasing the working voltage V0 can increase the sensitivity, and decreasing V0 can decrease the sensitivity. It can be adjusted according to actual needs during specific applications.

[0115] The differential amplifier DAM1 amplifies the voltage difference between the left and right variable resistors, and then drives the servo motor. After there is a steering action, a voltage difference appears between U1 and U2. After being amplified, it can drive the servo motor to rotate, thereby driving the right front wheel to rotate, synchronously driving the variable resistor R2 to rotate. Finally, the voltage difference reaches 0 within the error precision (assumed to be δ), that is, (-δ < U1 - U2 < δ), and the first motor M1 stops rotating. The first motor M1 is a DC servo motor. Figure 1 Using the output voltage of the differential amplifier DAM1 to directly drive the motor, or considering using a multi-stage amplifier or an integrated amplifier chip.

[0116] Of course, during the actual circuit design, it is necessary to consider both the power consumption and the sensitivity requirements. The deviation requirement of the steering angle does not belong to the high-precision requirement. Therefore, there is no need for too high sensitivity, and a suitable working voltage can be adopted.

[0117] In this embodiment, the pointers of the two conjugate variable resistors rotate in the opposite direction to ensure that there is always a 0 voltage difference (or within the preset deviation range) between them, that is, the steering angles of the left and right wheels always satisfy the Ackermann formula. The steering wheel controls the steering of one side of the wheel (assumed to be the left wheel. In this utility model, this assumption is defaulted for description. The simple mechanical transmission of the steering wheel will cause different left and right steering transmission ratios, which does not affect the function. To pursue consistency, a pair of non-circular gears with a characteristic parameter of c / 2 can be added to solve this problem). At the same time, through a 1:1 transmission, the sliding contact of the variable resistor rotates synchronously with the corresponding wheel. Here, the transmission ratio of the rotation angle of the motor to the rotation angle of the wheel is not limited and can be adjusted arbitrarily according to needs. The sliding contact of the left steering variable resistor rotates synchronously with the left front wheel. Since the corresponding conjugate variable resistor on the right does not rotate, the voltage balance is destroyed. The potential difference drives the steering servo motor to rotate through the amplifier circuit, quickly driving the right wheel to turn. When it rotates to meet the Ackermann formula, a new voltage balance is reached, the voltage difference drops to 0, and the motor stops rotating.

[0118] The principle of this solution is simple, the manufacturing is simple, and the cost is extremely low. Compared with traditional steering gears, the mechanical structure of the steering trapezoid is abandoned, so that the steering wheel only needs to control one-sided wheels. Therefore, the mechanical transmission structure becomes extremely flexible and variable.

[0119] In some embodiments, for realizing the front swing motion, since it is not restricted by the mechanical steering gear, only by switching the rheostat through an electronic switch, the left and right wheels can be steered synchronously in the reverse direction. Only need to turn the left wheel to the maximum angle to the right so that the turning center falls on the center of the rear wheel axle, then this function can be realized. At the same time, adjust the reverse movement of the left and right wheel power motors. Figure 1 On the basis of the basic steering circuit, add a reversing switch S1 as a mode switch to realize the corresponding function.

[0120] As Figure 2 shown, the control circuit includes a reversing switch S1 connected to the steering rheostat R1 and the steering rheostat R2. The forward gear position of the reversing switch S1 (as Figure 2 shown, connected to position 1) is used to make the steering rheostat R1 and the steering rheostat R2 conjugate symmetric. The reverse gear position of the reversing switch S1 is used to make the steering rheostat R1 and the steering rheostat R2 mirror symmetric.

[0121] When the reversing switch S1 is connected to the reverse gear position (as Figure 2 shown, connected to position 2), the inner resistance end of the steering rheostat R1 is connected to the positive pole of the power supply. When its sliding contact turns left, it moves towards the inner resistance end. The inner resistance end of the steering rheostat R2 is connected to the positive pole of the power supply. When its sliding contact turns left, it moves towards the outer resistance end.

[0122] At this time, the first motor M1 is used for: when the steering wheel turns right, correspondingly, the sliding contact of the steering rheostat R1 turns right, so that the potential U1 of the sliding contact of the steering rheostat R1 is less than the potential U2 of the sliding contact of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, drive the right front wheel to turn left, and at the same time drive the sliding contact of the steering rheostat R2 to turn left to eliminate the potential deviation. Moreover, the turning angle of the left front wheel is the same as the turning angle of the right front wheel.

[0123] Combined with Figure 2 , the circuit operation in different modes is described as follows:

[0124] Mode 1: Normal front wheel turning mode, the reversing switch S1 is connected to position 1

[0125] Steering rheostat access status: R1: outer positive left inner, R2: inner positive left outer, the two rheostats are always in a conjugate state;

[0126] Circuit operation analysis: The sliding contact of the steering rheostat R1 is synchronized with the rotation of the left front wheel. When the left front wheel turns left, the sliding contact moves towards the inner resistance area, and the value of U1 decreases. At this time, U1 < U2. According to Figure 1 Connection method of the middle motor and the amplifier: When the first motor M1 rotates counterclockwise, it drives the right front wheel to rotate counterclockwise, driving the steering rheostat R2 to rotate to the outer resistance area on the left side. The voltage U2 drops. When U1 is equal to U2, that is, the arc length of the steering rheostat R1 moving inward is equal to the arc length of the steering rheostat R2 moving outward, which means the steering angles of the left and right wheels satisfy the Ackermann formula. Similarly, when the steering wheel rotates clockwise and drives the left front wheel to rotate clockwise, the value of U1 rises. Correspondingly, U1 > U2, and the first motor M1 rotates clockwise, driving the steering rheostat R2 to move to the inner resistance area on the right side. U2 rises, and finally when U2 = U1, the Ackermann formula is satisfied.

[0127] Mode 2: Front swing motion mode, the changeover switch S1 is connected to position 2.

[0128] Connection state of the steering rheostats: R1: Inner positive and left inner, R2: Inner positive and left outer. The two rheostats are in a mirror-symmetrical manner.

[0129] Circuit operation analysis: When the left front wheel rotates clockwise, the steering rheostat R1 moves to the outer resistance area on the right side, and the value of U1 drops. U1 < U2, and the first motor M1 rotates counterclockwise, driving the right front wheel to rotate counterclockwise. The steering rheostat R2 moves in the outer resistance direction on the left side, and U2 drops. When U1 = U2, it means that both the steering rheostat R1 and the steering rheostat R2 rotate the same arc length to the outer resistance area, and the rotation angles must be equal, that is, the left wheel rotates clockwise and the right wheel rotates counterclockwise by the same angle. When rotating to a specific angle so that the turning center falls on the rear axle, the angle of the ideal front swing motion is achieved.

[0130] Power requirements: For a right swing, it is required that the left front wheel moves forward and the right front wheel moves backward at the same speed; for a left swing, the power direction is opposite. Manual control buttons can be added for left and right swings, and the rotation direction of the power motors of the left and right wheels can be changed to achieve this.

[0131] It should be noted that if the steering angle is insufficient, the turning center will fall in front of the rear axle. At this time, driven by the body rigidity, the rear wheels cannot achieve pure rolling and there will be sliding, and the whole vehicle rotates around the turning center at a low speed. Therefore, in the case of only front-wheel drive, in this embodiment, through mode switching, the front swing and rotation can be effectively achieved.

[0132] In some embodiments, for rotational motion and lateral movement, it is required that all four wheels support steering control. Two more steering rheostats need to be added to the vehicle steering control circuit to control the left and right rear wheels respectively to achieve this function.

[0133] As Figure 3 shown, the motor includes the second motor M2 and the third motor M3. The control circuit further includes the steering rheostat R3, the steering rheostat R4, and the mode control switch S2. The left rear wheel of the vehicle rotates synchronously with the steering rheostat R3, and the right rear wheel of the vehicle rotates synchronously with the steering rheostat R4.

[0134] The mode control switch S2 is used to control the steering resistors R3 and R4 to connect to or disconnect from the power supply.

[0135] The second motor M2 is used for: when the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns right, and accordingly, the sliding contact of the steering rheostat R1 turns right, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and when its potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn left to eliminate the potential deviation, and the left turn angle of the sliding contact of the steering rheostat R3 is the same as the left turn angle of the sliding contact of the steering rheostat R2.

[0136] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, and the steering wheel turns left, accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U3 of the steering rheostat R3, and when the potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn right to eliminate the potential deviation, and the right turn angle of the sliding contact of the steering rheostat R3 is the same as the right turn angle of the sliding contact of the steering rheostat R2.

[0137] The third motor M3 is used for: when the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, and the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U4 of the steering rheostat R4, and when its potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn right to eliminate the potential deviation, and the right turn angle of the sliding contact of the steering rheostat R4 is the same as the right turn angle of the sliding contact of the steering rheostat R1.

[0138] When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, and the steering wheel turns left, accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U4 of the steering rheostat R4, and when the potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn left to eliminate the potential deviation, and the left turning angle of the sliding contact of the steering rheostat R4 is the same as the left turning angle of the sliding contact of the steering rheostat R1.

[0139] Combination Figure 3 , description of circuit operation in different modes:

[0140] Rotation Mode:

[0141] The access states of the rheostats are as follows: R1: inner positive, left inner; R2: inner positive, left outer; R3: inner positive, left outer; R4: inner positive, left inner.

[0142] Circuit operation analysis: When the steering wheel turns right, the left front wheel turns right, and the steering rheostat R1 moves to the outer resistance area of the right turn, resulting in a decrease in U1. Subsequently, U1 < U2, driving the first motor M1 to turn left, driving the right front wheel to turn left, and driving the steering rheostat R2 to move to the outer resistance area of the left turn. Then U2 decreases. When U2 = U1, the right turn angle of the steering rheostat R1 is equal to the left turn angle of the steering rheostat R2, meeting the Fig.12 required rotation angle as analyzed. The steering rheostat R3 is the same as the steering rheostat R2. Since U1 < U3, the second motor M2 turns left, so the steering rheostat R3 also turns left by the same angle; since U1 < U4, the third motor M3 turns right, and the steering rheostat R4 turns right, with the same angle as the steering rheostat R1; ultimately meeting the rotation angle requirements.

[0143] Power analysis: When the vehicle body rotates to the right, the left wheels move forward and the right wheels move backward; when the vehicle body rotates to the left, the left wheels move backward and the right wheels move forward; the four wheels have the same speed.

[0144] Cross - shift mode:

[0145] The access states of the rheostats are as follows: R1: inner positive, left inner; R2: inner positive, left outer; R3: inner positive, left outer; R4: inner positive, left inner; that is, the access states of the rheostats in the cross - shift mode are the same as those in the rotation mode.

[0146] Circuit operation analysis: It has the same circuit relationship as the rotation mode. It is recommended to use the method of turning the steering wheel to the left. When the left front wheel turns left, U1 increases, the steering rheostat R2 turns right, the steering rheostat R3 turns right, and the steering rheostat R4 turns left. Ideally, it turns to 90°, and when limited by the maximum steering angle, it turns to the maximum angle.

[0147] Power analysis: When the vehicle body moves leftward in a cross - shift, the left and right front wheels move forward and the left and right rear wheels move backward; when the vehicle body moves rightward in a cross - shift, the left and right front wheels move backward and the left and right rear wheels move forward.

[0148] It can be understood that theoretically, turning the steering wheel to the right is completely the same as the rotation mode and can also meet the angle relationship of the cross - shift, but the power direction is opposite. Additionally, at this time, the maximum rotation angle of the steering wheel is limited by the maximum outer steering angle of the left front wheel, which is usually smaller than the maximum inner steering angle and has a greater deviation from the ideal value of 90°, resulting in increased tire wear and is not recommended.

[0149] In some embodiments, for the four - wheel turning mode, using series connection, a new pair of same - type steering rheostats R5 and R6 are added. Among them, the steering rheostat R5 and the steering rheostat R1 form a conjugate pair, the steering rheostat R6 and the steering rheostat R2 form a conjugate pair, and the steering rheostat R5 and the steering rheostat R6 are coaxially flipped and connected in series, taking the resistance wire scheme structure as an example.

[0150] like Figures 9 to 11 As shown, two rheostats can form a series unit by simply connecting coaxially and in a layered manner symmetrically along the X axis. When the sliding contact of one of the steering rheostats R5 and R6 enters the inner resistor end, the sliding contact of the other one enters the outer resistor end synchronously, and the rotation angles are equal. In other words, when one rheostat contact enters the inner steering zone, the other rheostat contact enters the outer steering zone synchronously, with equal angles, to achieve 1:1 transmission. A micro motor can be used to simultaneously drive the contacts of rheostats R5 and R6 to rotate synchronously.

[0151] like Figure 4 As shown, the motor includes a fourth motor M4, and the control circuit also includes a coaxially flipped series connected steering resistor R5 and a steering resistor R6. The fourth motor M4 is used to drive the steering resistor R5 and the steering resistor R6 to steer, so that the four wheels meet the Ackerman formula, thereby realizing a four-wheel turning mode.

[0152] Based on the above embodiment, the control circuit further includes a control switch S31, a control switch S32, a control switch S33 and a reversing switch S34.

[0153] The control switch S31 is connected between the power supply and the steering resistor R5 and the steering resistor R6, and is used for connecting or disconnecting the steering resistor R5 and the steering resistor R6.

[0154] The control switch S32 is connected to the first motor M1, the steering rheostat R1 and the steering rheostat R6, and is used to switch the potential reference signal for driving the right front wheel to steer between the sliding contact potential U1 and the sliding contact potential U6 of the steering rheostat R6.

[0155] The control switch S33 is connected to the third motor M3, the steering rheostat R1 and the steering rheostat R2, and is used to switch the potential reference signal for driving the right rear wheel to steer between the sliding contact potential U1 and the sliding contact potential U2.

[0156] The reversing switch S34 is connected to the second motor M2, the steering rheostat R1, and the steering rheostat R3. The forward gear of the reversing switch S34 is used to drive the second motor M2 to turn the left rear wheel left when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range. The reverse gear of the reversing switch S34 is used to drive the second motor M2 to turn the left rear wheel right when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range.

[0157] The fourth motor M4 is used when the commutation switch S1 is connected to the forward gear, the mode control switch S2 is closed, the control switch S31 is closed, the control switch S32 is connected to the sliding contact potential U6, the control switch S33 is connected to the sliding contact potential U2, the commutation switch S34 is connected to the reverse gear, and the steering wheel turns left. Accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U5 of the steering rheostat R5, and when the potential deviation exceeds the preset deviation range, it drives the steering rheostats R5 and R6 to turn left, so that the sliding contact potential U6 drops, and then the four-wheel turning mode is realized.

[0158] Combined with Figure 4 , the circuit operation of the four-wheel turning mode is described as follows:

[0159] According to the corresponding steering requirements, the four-wheel turning mode adds control switches S31, S32, S33, and S34 on the basis of the circuit shown in Figure 3 . Among them, S31 controls the connection and disconnection of the newly added steering rheostats R5 and R6. S32 and S33 switch the reference voltages of the right front wheel and the right rear wheel from the sliding contact potential U1 to the sliding contact potential U6 and the sliding contact potential U2 respectively, so that the right front wheel and the left front wheel conform to the four-wheel Ackermann, and the steering angles of the right rear wheel and the right front wheel are equal. S34 is a commutation switch to change the steering of M2 to meet the four-wheel turning requirements.

[0160] Rheostat connection status: R1: positive outside and left inside; R2: positive inside and left outside; R3: positive outside and left outside; R4: positive inside and left inside; R5: positive inside and left outside; R6: positive outside and left inside.

[0161] Circuit operation analysis: When the steering wheel turns left, the left front wheel turns left, and the steering rheostat R1 moves to the left inner resistance area. U1 drops, U1 < U5, which drives the fourth motor M4 to turn left, driving the steering rheostats R5 and R6 to turn left. U6 drops, U6 < U2, which drives the first motor M1 to turn left, driving the right front wheel to turn left, driving the steering rheostat R2 to turn left, and making U2 drop, finally making U1 = U5. When U6 = U2, it is balanced, ctg(R1)+a / b = ctg(R5) = ctg(R6) = ctg(R2)-a / b; that is, ctg(R1)+2a / b = ctg(R2); that is, the steering rheostat R1 and the steering rheostat R2 satisfy the four-wheel Ackermann formula. At the same time, U1 < U3, the commutation switch S34 is connected to position 2, the second motor M2 turns right, and the steering rheostat R3 moves to the right inner resistance area, resulting in U3 dropping. Finally, when U3 = U1, a balanced state is reached, that is, the steering rheostats R1 and R3 both move the same angle into the inner resistance area. The steering rheostat R1 turns left and the steering rheostat R3 turns right, that is, in the opposite direction, which conforms to Fig.16The required four-wheel turning angles analyzed. At the same time, since U2 < U4, the third motor M3 turns right, the steering rheostat R4 turns outward to the right, and U4 decreases. When U4 = U2, the turning angle of the steering rheostat R2 turning outward to the left resistance area is equal to the turning angle of the steering rheostat R4 turning outward to the right resistance area, exactly meeting the angle requirements; that is, ctg(R4) = ctg(R2) = ctg(R3) + 2a / b; Therefore, the overall four wheels satisfy the four-wheel Ackermann formula.

[0162] When the steering wheel turns right, similarly, only the direction is opposite, and the angle relationship all satisfies the four-wheel Ackermann formula.

[0163] As an option, the mode control switch S2 can also synchronously control the working power supplies of the differential amplifier DAM2 and / or the differential amplifier DAM3. The control switch S31 can also synchronously control the working power supply of the differential amplifier DAM4. All working power supplies are controlled by the vehicle start switch.

[0164] The relationship between each mode of the present invention and the control switch is shown in Table 1.

[0165]

[0166] Table 1 Mode Switch Control Relationship Table

[0167] The present invention designs a non-circular curve using mathematical analysis methods, designs a specific steering rheostat with this curve, makes the movement trajectory of its sliding contact conform to this curve, converts the steering angle into an electrical signal, and through the circuit combination of multiple steering rheostats, cooperating with circuit switches, realizes the functions of front-wheel turning, four-wheel turning, front swing, rotation, and lateral movement. This solution can theoretically strictly satisfy the Ackermann formula within the interval (-180, 180), increases the maximum steering angle, and at the same time, the steering wheel only needs to control one wheel, making the transmission design and installation more flexible. The mechanical and electrical cooperation has high reliability and low cost.

[0168] It can be understood that according to the linear superposition characteristics of the Ackermann formula, since this curve strictly satisfies this formula mathematically, it also has linear superposition characteristics.

[0169] ctg(α) + x = ctg(β);

[0170] ctg(β) + y = ctg(γ);

[0171] Then ctg(α) + x + y = ctg(γ);

[0172] Therefore, rheostats with different characteristic parameters can be connected in series to obtain a circuit with ideal steering requirements.

[0173] For the design of sports vehicles with four-wheel steering, the rotation centerline of the turning center is located in the middle of the front and rear axles, and the length-to-width ratio is reduced by half. This can be solved by using a series solution based on the front-wheel steering.

[0174] If the front and rear wheel tracks are different, the front and rear wheels need independent steering resistors. A pair of special steering resistors can be connected in series between the two groups. The analysis is as follows:

[0175] like Fig.12 As shown, it is a schematic diagram of the relationship between the four-wheel turning angles. In the four-wheel turning mode, the turning center is set on the horizontal center line. The inner steering angle of the front wheel is α1, the outer steering angle is β1, the inner steering angle of the rear wheel is α2, and the outer steering angle is β2. The angle relationship formula is ctg(α1)=ctg(α2)+(a2-a1) / b. Obviously, this formula is also the Ackerman formula, but the aspect ratio is different, that is, the corresponding curve characteristic parameters are different. Therefore, under different front and rear wheel widths, the relationship between the steering angles of the front and rear wheels on the same side also conforms to the Ackerman formula. The front and rear aspect ratio difference (a2-a1) / b can be used as the curve characteristic parameter, and the correct steering requirements can be achieved by series connection. Another example Fig.12 As shown, it is obvious that in the four-wheel turning mode, the front wheel steering angle relationship formula is ctg(α1)=ctg(β1)-2a1 / b; compared with the traditional front wheel steering Ackerman formula ctg(α1)=ctg(β1)-a1 / b, the same aspect ratio curve can be used in series. Similarly, the rear wheel steering angle relationship formula is ctg(α2)=ctg(β2)-2a2 / b, and the rear wheels can also be connected in series. In actual models, the front and rear wheel tracks are not much different. After fitting data analysis, (a2-a1) / b<0.025, then α1 is in the range of [0,90°], and α1-α2 does not exceed 1.43°. This difference can be completely ignored, which can greatly simplify the actual solution. This difference is not considered in this solution.

[0176] like Fig.13 The figure shows the steering angle and wheel movement direction of the front swing mode. The right figure shows the ideal angle. The turning center of the left and right front wheels falls exactly on the center point of the rear wheel axle. At this time, all four wheels are in pure rolling. The left figure shows the schematic diagram of the steering angle being insufficient. At this time, the four wheels are sliding and the body movement is close to completing the front swing movement. In the front swing mode, the front wheel steering angle is required to be symmetrical, and the power requires the left and right front wheels to move in opposite directions. Therefore, the front swing is more suitable for independent motor drive of the left and right front wheels.

[0177] like Fig.14The figure shows the steering angle and wheel movement direction in the rotation mode. The rotation mode requires that all four wheels support steering, and the power requirement is preferably four-wheel drive. Two-wheel drive can also achieve rotation. The left picture shows the ideal angle, that is, the turning center of the four wheels is exactly at the fork of the four-wheel diagonal lines, and at this time all four wheels are pure rolling. The right picture shows that the steering angle is insufficient, the turning center of the front wheel does not coincide with the turning center of the rear wheel, and the wheel will slide, and the whole vehicle will almost complete the rotation. In the rotation mode, the steering angle is required to be symmetrical left and right and symmetrical front and back. The power requirement is that the left and right wheels move in opposite directions, and the front and rear wheels on the same side move in the same direction.

[0178] like Fig.15 The figure shows the steering angle and wheel movement direction of the lateral mode. The lateral mode requires four wheels to support steering and four wheels to be driven independently. The left figure shows that the left and right front wheels turn outward, the front and rear wheels turn symmetrically, the diagonal wheels move in the same direction, and the adjacent wheels move in opposite directions, which can achieve lateral movement of the entire vehicle body. The right figure shows that the left and right front wheels turn inward, and the steering angle is also required to be symmetrical front and rear. The power requires that the diagonal wheels move in the same direction and the adjacent wheels move in opposite directions. Under ideal conditions, that is, when the steering angle is 90°, the four wheels roll purely and move sideways. The steering angle is limited to less than 90°. Generally, the maximum inner steering angle is greater than the outer steering angle. It is recommended to use outward steering in the lateral mode, that is, each wheel reaches the maximum inner steering angle.

[0179] like Fig.16 The figure shows the steering angle and wheel movement direction of the four-wheel turning mode. This mode requires four wheels to support steering and four wheels to be driven independently. The relationship between the steering angles is symmetrical between the front and rear steering angles on the same side, and the steering angle between the left and right wheels conforms to the Ackerman formula for four-wheel turning.

[0180] For the rotation mode, ideally, the maximum steering angle of the wheel should reach the angle between the four-wheel diagonal line and the horizontal line, so that the turning center coincides with the intersection of the four wheels. If the steering angle is insufficient, the turning centers of the front and rear wheels will not coincide. Driven by the rigidity of the vehicle body, rotation can still be achieved on the spot, but the wheel cannot achieve pure rolling, and there will be wheel sliding, which will also cause some pressure on the frame.

[0181] like Fig.17 As shown, compared with the rotation scheme (named X scheme) that uses the reverse movement of the left and right wheels in the current models on the market, the sliding wear and pressure on the frame are much smaller.

[0182] The wheelbase to track ratio Taking the vehicle model as an example, assume that this solution can turn 40° (the maximum steering angle of the inner side of a common small car is about 40°). The wheel speed is V, the motor power is F, and according to the geometric relationship, vector decomposition is performed. It is easy to obtain that the ratio of the effective velocity component in the pure rolling direction of the X solution is cos(60°), that is, 0.5V, and the ratio of the harmful sliding velocity component is sin(60°), that is, 0.866V. Similarly, the effective power component is 0.5F, and the harmful pressure (tension) on the frame is 0.866F; this solution is the effective velocity component in the pure rolling direction cos(20°), that is, 0.94V, and the harmful sliding velocity component sin(20°), that is, 0.34V. The effective power component is 0.94F, and the harmful pressure component on the frame is 0.34F.

[0183] Under the same safety conditions, the maximum rotation speed ratio is about 0.866 / 0.34*0.94 / 0.5=4.79 times, which means that the maximum rotation speed of this solution is 4.79 times that of the X solution, which greatly improves the experience; if the constraints of other mechanisms are eliminated and the steering angle reaches 50°, the invalid or harmful component will be further reduced by nearly half, and the maximum rotation speed will reach nearly 10 times that of the X solution, so that the purpose of passing can be achieved by rapid rotation. When it reaches 60°, it becomes an ideal state and completely eliminates the harmful component.

[0184] For the lateral mode, the ideal steering angle is 90°. If the actual steering angle cannot be reached, assuming the deviation angle is x, the same analysis as above shows that the harmful component ratio is sin(x). Obviously, the smaller x is, the less tire wear there is. The maximum steering angle is recommended to be above 65°, and the ratio of the effective component to the harmful component will be greater than 2. When used at low speed and short distance for storage, the wear is acceptable.

[0185] This embodiment converts the angle relationship satisfying the Ackerman formula into a voltage balance relationship between two variable resistor sliding contacts to drive the wheel steering, thereby avoiding the constraints of the Ackerman steering trapezoidal connecting rod in the prior art and having the advantages of simple structure, convenient steering, strong flexibility and high reliability.

[0186] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should belong to the scope covered by the claims of the utility model.

Claims

1. A vehicle steering control circuit, characterized in that: The invention comprises at least one motor and at least two steering resistors connected to the motor; The motion trajectory of the sliding contact of the steering resistor satisfies a non-circular curve, and the non-circular curve satisfies equation (I): (r(α)=d / (2+c*sin(2α)+c 2 sin 2 (α)) or the equivalent equation of equation (I); Among them, r is the polar diameter; α is the polar angle; c is a constant related to the ratio of the wheelbase to the wheelbase of the car, which is related to the shape of the steering resistor; d is the center distance between the two non-circular curves, which is related to the size of the steering resistor; The steering rheostat is used to convert the steering angle of the car into the resistance value of the sliding contact end, and then convert the resistance value of the sliding contact end into a voltage signal according to the resistance voltage division principle; wherein the resistance value of the steering rheostat is positively correlated with the arc length of the sliding contact; The motor is used to drive the corresponding wheels of the vehicle to steer according to the potential difference between the sliding contact ends of at least two steering rheostats.

2. The automobile steering control circuit according to claim 1, characterized in that: The steering resistor comprises a sliding contact, a breakpoint and a body, wherein the body is an insulating core whose shape conforms to the non-circular curve, and a resistance wire is wound on the insulating core; or, the body is a resistor sheet whose shape conforms to the non-circular curve; The breakpoint is set near the polar angle of 180°, with the polar angle of 0° in the polar coordinate system as the starting point, the area above the starting point is the inner resistor end, and the area below the starting point is the outer resistor end; The sliding contact is one of a sliding sheet, a resistance wire or a resistance sheet.

3. The automobile steering control circuit according to claim 2, characterized in that: The motor includes a first motor, the control circuit includes a conjugate symmetrical steering rheostat R1 and a steering rheostat R2, the left front wheel of the car rotates synchronously with the steering rheostat R1, and the right front wheel of the car rotates synchronously with the steering rheostat R2; The outer resistance end of the steering rheostat R1 is connected to the positive pole of the power supply, and its sliding contact moves to the inner resistance end when it turns left; The inner resistance end of the steering rheostat R2 is connected to the positive pole of the power supply, and its sliding contact moves toward the outer resistance end when it turns left; The first motor is used to drive the right front wheel to steer when the potential difference between the sliding contact ends of the steering rheostat R1 and the steering rheostat R2 exceeds a preset deviation range, and drives the sliding contact of the steering rheostat R2 to rotate until the potential difference is within the preset deviation range, and then stops driving.

4. The automobile steering control circuit according to claim 3, characterized in that: The first motor is used for: When the steering wheel turns left, the sliding contact of the steering rheostat R1 turns left accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn left to eliminate the potential deviation; When the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn right to eliminate the potential deviation.

5. The automobile steering control circuit according to claim 3, characterized in that: The control circuit includes a reversing switch S1 connected to the steering rheostat R1 and the steering rheostat R2, wherein the forward gear of the reversing switch S1 is used to make the steering rheostat R1 and the steering rheostat R2 conjugate symmetrical; the reverse gear of the reversing switch S1 is used to make the steering rheostat R1 and the steering rheostat R2 mirror symmetrical; When the reversing switch S1 is connected to the reverse gear, the inner resistance end of the steering rheostat R1 is connected to the positive electrode of the power supply, and its sliding contact moves to the inner resistance end when it turns left, and the inner resistance end of the steering rheostat R2 is connected to the positive electrode of the power supply, and its sliding contact moves to the outer resistance end when it turns left; At this time, the first motor is used for: When the steering wheel turns right, the sliding contact of the steering rheostat R1 turns right accordingly, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U2 of the steering rheostat R2, and when the potential deviation exceeds the preset deviation range, the right front wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R2 is driven to turn left to eliminate the potential deviation, and the angle at which the left front wheel turns right is the same as the angle at which the right front wheel turns left.

6. The automobile steering control circuit according to claim 5, characterized in that: The motor includes a second motor and a third motor, and the control circuit also includes a steering rheostat R3, a steering rheostat R4 and a mode control switch S2, the left rear wheel of the car rotates synchronously with the steering rheostat R3, and the right rear wheel of the car rotates synchronously with the steering rheostat R4; The mode control switch S2 is used to control the steering rheostat R3 and the steering rheostat R4 to connect to or disconnect the power supply; The second motor is used for: When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns right, and accordingly, the sliding contact of the steering rheostat R1 turns right, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and when the potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn left to eliminate the potential deviation, and the left turning angle of the sliding contact of the steering rheostat R3 is the same as the left turning angle of the sliding contact of the steering rheostat R2; When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns left, and accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U3 of the steering rheostat R3, and when the potential deviation exceeds the preset deviation range, the left rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R3 is driven to turn right to eliminate the potential deviation, and the right turning angle of the sliding contact of the steering rheostat R3 is the same as the right turning angle of the sliding contact of the steering rheostat R2; The third motor is used for: When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, the steering wheel turns right, and accordingly, the sliding contact of the steering rheostat R1 turns right, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U4 of the steering rheostat R4, and when the potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn right, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn right to eliminate the potential deviation, and the right turning angle of the sliding contact of the steering rheostat R4 is the same as the right turning angle of the sliding contact of the steering rheostat R1; When the reversing switch S1 is connected to the reverse gear, the mode control switch S2 is closed, and the steering wheel turns left, accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is greater than the sliding contact potential U4 of the steering rheostat R4, and when the potential deviation exceeds the preset deviation range, the right rear wheel is driven to turn left, and at the same time, the sliding contact of the steering rheostat R4 is driven to turn left to eliminate the potential deviation, and the left turning angle of the sliding contact of the steering rheostat R4 is the same as the left turning angle of the sliding contact of the steering rheostat R1.

7. The automobile steering control circuit according to claim 6, characterized in that: The motor includes a fourth motor, and the control circuit also includes a steering resistor R5 and a steering resistor R6 which are coaxially reversed and connected in series; Among them, the steering resistor R5 forms a conjugate pair with the steering resistor R1, and the steering resistor R6 forms a conjugate pair with the steering resistor R2; when the sliding contact of one of the steering resistor R5 and the steering resistor R6 enters the inner resistance end, the sliding contact of the other one enters the outer resistance end synchronously, and the rotation angles are equal; The fourth motor is used to drive the steering rheostat R5 and the steering rheostat R6 to steer, so that the four wheels satisfy the Ackerman formula, thereby realizing a four-wheel turning mode.

8. The automobile steering control circuit according to claim 7, characterized in that: The control circuit also includes a control switch S31, a control switch S32, a control switch S33 and a reversing switch S34; The control switch S31 is connected between the power supply and the steering resistor R5 and the steering resistor R6, and is used to connect or disconnect the steering resistor R5 and the steering resistor R6; The control switch S32 is connected to the first motor, the steering rheostat R1, and the steering rheostat R6, and is used to switch the potential reference signal for driving the right front wheel to steer between the sliding contact potential U1 and the sliding contact potential U6 of the steering rheostat R6; The control switch S33 is connected to the third motor, the steering rheostat R1, and the steering rheostat R2, and is used to switch the potential reference signal for driving the right rear wheel to steer between the sliding contact potential U1 and the sliding contact potential U2; The reversing switch S34 is connected to the second motor, the steering rheostat R1, and the steering rheostat R3. The forward gear of the reversing switch S34 is used to drive the second motor to turn the left rear wheel left when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range; the reverse gear of the reversing switch S34 is used to drive the second motor to turn the left rear wheel right when the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U3 of the steering rheostat R3, and the potential deviation thereof exceeds the preset deviation range; The fourth motor is used for: When the reversing switch S1 is connected to the forward gear, the mode control switch S2 is closed, the control switch S31 is closed, the control switch S32 is connected to the sliding contact potential U6, the control switch S33 is connected to the sliding contact potential U2, the reversing switch S34 is connected to the reverse gear, the steering wheel turns left, and accordingly, the sliding contact of the steering rheostat R1 turns left, so that the sliding contact potential U1 of the steering rheostat R1 is less than the sliding contact potential U5 of the steering rheostat R5, and when the potential deviation exceeds the preset deviation range, the steering rheostat R5 and the steering rheostat R6 are driven to turn left to reduce the sliding contact potential U6, thereby realizing the four-wheel turning mode.

9. The automobile steering control circuit according to claim 1, characterized in that: The control circuit further comprises at least one differential amplifier, wherein two input terminals of the differential amplifier are correspondingly connected to sliding contact terminals of two steering resistors, and an output terminal of the differential amplifier is connected to the motor, and each motor corresponds to one differential amplifier; or The control circuit further comprises at least one voltage comparator, two input ends of the voltage comparator are correspondingly connected to the sliding contact ends of the two steering resistors, and the output end of the voltage comparator is connected to the motor to control the power relay switch of the motor; or The control circuit also includes a digital circuit module, the input end of the digital circuit module is connected to the sliding contact ends of two steering resistors, the output end of the digital circuit module is connected to the motor, and the digital circuit module is used to digitize the potential difference to drive the motor to turn in a corresponding direction.

10. An automobile, characterized in that: The vehicle steering control circuit comprises the vehicle steering control circuit as claimed in any one of claims 1 to 9.

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