Automatic control driving method for bicycle-type vehicles

Abstract

This invention discusses relevant aspects of the operating principles of bicycles and, from there, devised a method for bicycle-type vehicles (vehicles with front and rear wheels, such as bicycles, electric bicycles, and motorcycles) to travel according to directional requirements in an automatic control mode. [Solution] This replaces the driver's vehicle balance sensing and control actions. In this invention, a straight line determined by the ground contact points of the bicycle's two wheels is used as the axis of rotation, and the rotational motion of the vehicle body relative to this axis is controlled by controlling the change in the steering angle of the directional wheels through the measurement and calculation of related variables. Control requirements for this motion are set in combination with travel direction adjustment requirements, thereby unifying vehicle balance control and travel direction adjustment.

Description

Technical Field

[0001] The present invention relates to the automatic driving control management of a bicycle-type vehicle (two-wheeled vehicles such as bicycles, electric bicycles, and motorcycles, or land transportation tools having an enclosed passenger space and a support leg device developed from these vehicle types, hereinafter all abbreviated as bicycles). In particular, based on the direction requirement and the related running state, the bicycle is continuously adjusted to an effective running state, the relative balance of the running vehicle is judged, and the related requirements regarding automatic driving can be achieved.

Background Art

[0002] Currently, common personal land transportation methods have several problems. Bicycles require the rider to sense and control their own balance, and to cope with the lateral tilting problems that occur at low speeds or when stopped, the user usually needs to utilize the force between their legs and the ground. As a result, the rider and passenger cannot be in a completely enclosed space, and the use of this type of vehicle is greatly affected by the environment, making it very inconvenient in bad weather (extreme cold, extreme heat, wind and rain, etc.). Relatively small three-wheeled or four-wheeled vehicles have narrow lateral treads, making it difficult to cope with lateral undulations and situations with large centrifugal forces when turning, limiting their performance and spatial placement. Automobiles occupy many resources, occupy a large area, have high energy consumption during use and production costs, and cause a series of problems such as congestion, difficulty in parking, and soaring travel costs. Statistics show that most automobiles on the road have only one person in them, and it is rare for three or more people to use one car at the same time, which is a clear indication of resource waste. If an effective method exists to automatically detect and control the balance of a moving bicycle, it would be possible to equip it with a device (support leg mechanism) that replaces the driver's leg function and activate it when needed, allowing the driver and passengers to be in a completely enclosed space. This would enable the application of this type of vehicle to adapt to diverse environmental conditions and improve safety and other aspects of its configuration. The enclosed space facilitates the acquisition of a low-wind resistance shape for this type of vehicle, improving efficiency during (especially high-speed) driving. The application of automatic driving control reduces the effort the driver spends on balance control, improves riding posture and steering methods, and is a necessary condition for realizing autonomous driving of this type of vehicle. In conclusion, realizing automatic driving control for this type of vehicle will greatly unleash its potential, achieve relative advantages in terms of comfort, convenience, energy saving, economy, and space utilization, conserve relevant social resources, and realize greater application value. [Overview of the project] [Problems that the invention aims to solve]

[0003] To achieve automatic judgment and control of the balance state of a bicycle while it is in motion, the present invention provides a method for monitoring and adjusting related elements by identifying relevant factors that affect its operation based on the unique structure and motion characteristics of a bicycle, and by analyzing the relationship of changes between active and passive variables within those factors, thereby achieving the objective of enabling a machine to effectively recognize and control the riding state of a bicycle.

[0004] Citation of analysis methods and related content When a bicycle is in motion, the plane supporting its motion (usually the ground, hereinafter abbreviated as the ground) has two points of contact (hereinafter abbreviated as contact points) with the bicycle's two wheels. In this specification, the line connecting these two contact points is considered the axis of rotation (hereinafter abbreviated as the contact point axis), and the operation of the bicycle is analyzed in relation to the rotational motion of the vehicle body around the contact point axis. As shown in Figure 1-i (Figure 1i, hereinafter the same), the two points of contact between the bicycle's wheels and the ground are A and B. To facilitate the description of the vehicle state, the straight line BA is vectorized, and its direction is from B to A. When the bicycle is in motion, if the angle between the forward direction of its center of gravity and the direction of vector BA is less than 90 degrees, A is defined as the front and B as the rear. In this specification, we will first analyze a typical bicycle structure as an example. The front wheel of this bicycle is the steering wheel, and CJ is the axis of rotation of the front wheel (direction axis, rotation axis, control axis, etc.). The rear wheel cannot rotate actively, and the axes of the front and rear wheels are points C and D, with their distance from each other remaining constant. The line of intersection between the plane on which the front wheel is located (hereinafter abbreviated as the front wheel plane) and the ground is AR, and that of the rear wheel is BK. In this specification, the conditions for riding a bicycle are that the wheels roll on the ground without slipping, that is, points A and B do not move in a direction perpendicular to AR and BK. In this specification, the plane formed by the center of gravity of the bicycle and the axis of contact with the ground is called the center of gravity plane, and the plane when the front and rear wheels are in the same plane, or the plane of symmetry of the bicycle with respect to the left and right directions (plane JCD in Figure 1-i), is called the body plane. The rotational speed of the bicycle body, i.e., its center of gravity plane, in the space centered on the axis of contact with the ground is called the body angular velocity (denoted by ω), and the rate of change of ω (derivative) is the body angular acceleration (denoted by ω'). In this specification, the motion of the vehicle is described from a view from the rear of the vehicle. When the vehicle rotates counterclockwise, ω is represented by a positive value (+), and when it rotates counterclockwise, it is represented by a negative value (-). When ω increases, ω' is represented by a positive value (+), and when it increases, it is represented by a negative value (-). In this specification, the direction and magnitude of the vehicle's angular velocity and angular acceleration are collectively referred to as the vehicle's rotational state.

[0005] Representation of steering angle and target steering angle As shown in Figure 1-ii, the angle between the front wheel surface and the body surface of the bicycle is represented by the angle ∠TOY (denoted by α) between OT and OY on the coordinate axis. When OT and OY coincide, i.e., when α is 0, the front wheel surface and the body surface coincide, and in this state the bicycle maintains a straight line on flat ground (in Figure 1-i, AR and BK are collinear). When the bicycle turns left, i.e., when OT is to the left of OY, the angle of α is represented by a positive value (+), and when it is relatively to the right, it is represented by a negative value (-). In this way, the magnitude of α can indicate the direction of travel angle (angle of travel, steering angle, etc.). Using OT' and the angle it forms with OY ∠YOT' (denoted by α0), the target direction of travel (destination direction, required direction, etc.) that the vehicle is currently receiving is indicated, and the magnitude of α0 is the target steering angle, and its value is expressed in the same way as α.

[0006] Change in force on the contact point axis due to change in α As shown in Figure 1-i, if the line AR, which is the intersection of the front wheel surface and the ground, has another intersection point A1 with the front wheel, then A1 would exist simultaneously on both the wheel and the ground, which is not true. Therefore, it can be proven that there is only one intersection point between AR and the wheel, meaning that AR and the wheel are in contact. Assuming that the conditions affecting the curvature of the two contact points A and B during bicycle operation—namely, the angle α between the front wheel surface and the frame surface, and the angle between the frame surface and the ground—are constant, and that the ground is flat and undeformed, then the trajectory of the contact points in this state will be either a straight line or a circle. Figure 1-iii shows the case where the trajectories of A and B are circles under the above conditions, and their arcs are AA' and BB', respectively. The center of AA' is O1, connecting A and O1. The related geometric relationships formed in this state remain constant, meaning that the angle between AO1 and AR is always equal. Therefore, if AR has another intersection point A' with arc AA', we connect O1A' and obtain ∠RAO1 = ∠RA'O1. Since ∠RAO1 = ∠RA'O1 + ∠A'O1A and ∠A'O1A > 0, ∠RAO1 = ∠RA'O1 does not hold, thus proving that there is only one intersection point between AR and AA', i.e., if the locus of point A is not a straight line, AR is always tangent to the trajectory of point A. Connect O1B. Due to the invariance of geometric relationships, the lengths of AB and AO1 and the magnitude of ∠O1AB remain unchanged, so the length of O1B is also invariant, i.e., O1 is also the center of arc BB'. In Figure 1-iii, assume that the line of intersection BK between the rear wheel surface and the ground intersects AR at point K. While cycling, BK and BA do not always coincide, but the angle and influence between them are relatively small. Here, we will first ignore this difference and consider AB and KB to be collinear. This leads to AB ⊥ O1B and ∠AO1B = ∠RAB. While cycling, ∠RAB and α usually do not change in a 1:1 ratio, but the proportionality constant is positive. We set ∠RAB = λα (the magnitude of λ is related to the current value of α, the structure of the bicycle, and the angle between the bicycle surface and the ground, and is usually between 0.6 and 1.0). Let d represent the length of line segment AB. This length changes while cycling, but it is relatively small, so we will ignore it here. AO1 and BO1 are the radii of curvature of points A and B, and are represented by RA and RB, respectively.This yields RA = d / sin(λα) and RB = d / tan(λα). Let VA and VB be the velocities of points A and B relative to the ground, respectively, and use the formula for centripetal acceleration a = V. 2 According to / R, the magnitudes of the centripetal accelerations at points A and B are sin(λα)·VA, respectively. 2 / d, tan(λα)·VB 2 / d. If we set the change in α within a small time interval dt as dα, the changes in the centripetal acceleration of points A and B are sin(λdα)·VA, respectively. 2 / d and tan(λdα)·VB 2 / d is such that the change in the direction perpendicular to AB is tan(λdα)·VB for both. 2 The equation is / d. This indicates that when a bicycle is in motion, changing the magnitude of α can change the lateral acceleration of the contact point axis (along the direction of the ground), meaning that the lateral force acting from the ground on the contact point axis changes. This change is not only affected by the change in α, but is also proportional to the square of the vehicle speed.

[0007] Relationship between the change in α and the vehicle's angular acceleration As shown in Figure 1-iv, point O is the center of gravity of the vehicle, vector OG is the gravitational force acting on the bicycle, vector OL is the relative inertial force of the vehicle when AB accelerates laterally along the ground, and vector ON is the resultant force of other external forces acting on the bicycle, such as wind. OF is the projection of the vector sum of vectors OG, OL, and ON onto a plane perpendicular to AB. In Figure 1-v, a perpendicular line OP is drawn from point O to the contact point axis AB, and the intersection point is P. The plane HAB represents the plane of motion of the contact point axis AB, and HP ⊥ AB. On the plane OPH, construct OM ⊥ OP and MF ∥ OP. OP is used to represent the orientation of the vehicle in the direction perpendicular to AB, and vector OM is used to represent the component of OF in the direction perpendicular to OP. Without considering changes in other elements, taking the case where α is positive and increasing as an example, the contact point axis AB or point P is subjected to a force that increases in the HP direction (leftward). If we let vector PE be the change in force acting on point P, and vector OL' be the change in the corresponding inertial force of the vehicle body, then we can see that PE and OL' are equal but opposite in direction. The point of application of vector PE is not at the center of gravity of the vehicle body, and there is no even of the corresponding force, so this force causes changes in both rotational and translational acceleration of the vehicle body OP. The change in the translational motion of the vehicle body (OQ in Figure 1-v) is smaller than itself or OL'. The difference between OL' and OQ is represented by OS, and OF' and OM' show the results of OF and OM after the change. In this way, through the change in α, an asymmetrical change occurs in the force acting on the vehicle body in the vertical direction, the angular acceleration of the vehicle body changes accordingly, and consequently, control of the vehicle body's angular velocity becomes possible. OF or OF' can be considered as the resultant force acting on the vehicle body with respect to the contact point axis. The product of OP and OM (or OM') can be considered as the magnitude of the relative moment acting on the vehicle body with respect to the contact point axis. If we consider the bicycle to be in a stationary state before α changes, then when α changes, it is equivalent to the ground swaying from side to side, and therefore this can also be considered an inverted pendulum model.

[0008] The influence of ground conditions on vehicle angular acceleration control The above discussion assumes that the bicycle is moving on a flat surface, but actual ground often has irregularities of varying degrees. However, the influence of the contact point axis on the vehicle's angular acceleration is related only to the current (instantaneous) force situation, and its motion trajectory can be considered to consist of an instantaneous motion plane that is constantly being formed. As long as the current motion plane formed by the contact point axis does not coincide with the center of gravity plane, a change in α causes a change in the vehicle's angular acceleration, and this control method is effective. A change in the angle between the center of gravity plane and the instantaneous motion plane of the contact point axis affects the control of the vehicle's angular acceleration, but this can be addressed by changing the rate of change of α. In Figures 1-i and 1-iii, AR and BK are on the instantaneous motion plane formed by the contact point axis and can be considered to be changing in sync with the motion of the contact point axis, rather than on the actual ground. The influence of (very small) changes in the length of AB and the magnitude of ∠ABK on the force on the contact point axis can also be adjusted within the change in α. This also shows that cycling does not require specially prepared surfaces and can handle most road conditions.

[0009] Secondary effects of alpha change As shown in Figure 1-i, AC and BD are considered typical paths through which interaction forces are transmitted between the bicycle frame and the ground. In Figure 1-vi, ∠DPC (∠DBC, ∠DAC) is the angle made by AC and BD in the direction perpendicular to AB (hereinafter abbreviated as the left-right direction). Normally, when a force is applied during bicycle operation to change α (at this time, the frame is divided into two parts that generate angular acceleration with AC as the axis of rotation), ∠DPC also changes, and points C and D exert interaction forces with A and B in the left-right direction. At this time, since A and B are in a state of acceleration change, the forces acting on points C and D are different, and as a result, the center of gravity O produces an acceleration effect in the same direction as point P. For example, when α is positive and increasing due to the applied force, the leftward acceleration of AB increases, the leftward force acting on point C becomes greater than the rightward force acting on point D, and overall a net leftward force is applied to point O, increasing the leftward acceleration. This effect reduces the change in vehicle angular acceleration caused by the change in α, and reduces the angle between the vehicle orientation (OP in Figure 1-v) and the relative resultant force (OF' in Figure 1-v). In most cases, the vehicle angular acceleration caused by the α fluctuation increases, so except in cases of very low vehicle speed, the resulting effect is advantageous for vehicle rotation control. All other things being equal, the magnitude of this effect is related to the vehicle structure. For example, in Figure 1-i, the smaller the angle between the steering wheel axis JC and CD, the larger the change in the angle between CA and DB when α changes, and the greater the effect of this phenomenon.

[0010] The effect of the gyroscopic effect As shown in Figure 2-i, a gyroscope with axis MN is rotating on a base. Point P is a point in space through which the outer edge of the gyroscope passes as it rotates, and point O is the center of the gyroscope. The plate surface is perpendicular to OP, and the plate maintains the same velocity and direction of motion as the gyroscope's point mass passing through point P. In this way, when the gyro plane or MN axis maintains the same spatial angle and position, the plate performs linear motion. On the other hand, when the gyroscope's axis MN rotates around OP, the direction of the plate's movement also constantly changes. Similar to Figure 2-ii, when there is no external force, the object maintains uniform linear motion (section A'B'). When there is a centripetal force F (section B'C'), the object develops curvature and rotates around O'. After the centripetal force is released (from point C' onward), the object continues uniform linear motion due to inertia. Changing the spatial angle of the rotating gyro plane (gyro axis) is equivalent to changing the curvature of motion of the point mass within the gyroscope. This means that when a gyroscope rotates, inertia keeps the spatial angle of the gyroscopic plane constant. Under external force, the gyroscopic plane rotates, and subsequently the gyroscope also generates a reaction force against the object applying the force. When a bicycle is in motion, its two wheels or other rotating mechanisms attached to the frame (such as motors) play a similar role to a gyroscope, i.e., they generate a force opposite to the rotation of the frame relative to the axis of contact with the ground. This effect helps to reduce the angular velocity of the frame, extends the reaction time required for system control, and also helps to stabilize fluctuations in α. However, the mass of rotating mechanisms such as wheels is usually small relative to the frame, and the effect is even more limited at low speeds. However, it is also possible to actively add this type of mechanism, i.e., equip the bicycle with gyro-like devices whose axis of rotation is relatively perpendicular to the axis of contact with the ground, and choose to keep them rotating at relatively high speeds when needed. This can increase the stability of the frame and reduce the difficulty of controlling the angular velocity of the frame. The rotational motion of the bicycle's axle or wheel surface in other directions is restricted by the frame (in Figure 1-i, the rotation of the front wheel surface around JC is controlled, and the rotation of the rear wheel surface around CD is controlled; these motions are constrained by the frame's motion), and the rotation of the frame along the ground is restricted by the frictional force between points A and B and the ground; therefore, these do not affect the change in the frame's angular velocity and will not be discussed here.

[0011] Control of vehicle angular velocity combined with direction request From the above analysis, it can be concluded that, given a constant vehicle speed, the force acting on the vehicle can be actively changed by changing α. By adjusting the rate of change of α at the appropriate timing to cope with unexpected factors under normal conditions (crosswinds, uneven ground, etc.), the magnitude of the vehicle's angular acceleration ω' can be controlled, and consequently, the vehicle's angular velocity ω can be controlled. In this way, by adjusting α in combination with the driver's demands for the current direction of travel, the rotation of the vehicle around the contact point axis can be controlled, and the demands of cycling can be met. As shown in Figure 2-iii, the X axis represents time, and the Y axis shows the variation of ω, ω', and α with respect to time. Assuming that the current target steering angle α0 is constant, the ideal demand for the vehicle's angular velocity is that ω is always zero, and the corresponding control target is to adjust ω to always approach zero. Starting from the origin O of the coordinate axes, the vehicle starts rotating counterclockwise due to the influence of crosswinds, and both ω and ω' increase. At point A, the control system starts feedback based on the changes in ω and ω', combined with the current vehicle speed. In other words, the angle of α begins to increase. Points B and C are inflection points for ω' and ω. Since dynamic adjustment is always underway, it is impossible and unnecessary to reach the target value completely. Therefore, once point E is reached and the vehicle's angular velocity approaches the target value, control at this stage can be terminated. During control, the rate of change of α depends on the situation. If ω and ω' increase rapidly after point A, it is necessary to increase the angular velocity of α to accelerate the arrival of the inflection points at points B and C. Conversely, if the increase is rapid, it is necessary to slow down the change of α. After point C, as the vehicle's angular velocity approaches the target value (see point D), it is necessary to adjust the rate of change of α so that ω' approaches 0. This makes it easier for ω to converge to the target value. If the inflection points of ω' and ω do not appear within the set time after point A, or if ω fluctuates greatly and does not easily approach the target value, it means that control has failed, and at this point intervention by other means (e.g., lowering the support legs) is necessary.

[0012] Regulation of average direction of travel When controlling the rotational state of the vehicle body, α must constantly change, and it is often in a dynamic cycle and does not coincide with the driver's directed direction angle α0. The present invention provides the average value of α within a certain historical period, or the average value within one change cycle ( The value represented by JPEG2026517249000002.jpg76 is used as the vehicle's direction of travel angle, not its current value (instantaneous value). Correspondingly, the average value of the vehicle's curvature over a certain historical period or one change cycle is used as the calculated value for that direction of travel. α0 and If JPEG2026517249000003.jpg76 matches (since these two values ​​are constantly changing, even very close matches can be considered a match), then overall (over a long period of time) the direction of travel and the direction of destination match, and the riding requirements of the bicycle can be met. α0 and Difference in JPEG2026517249000004.jpg76 (α0 - The size of JPEG2026517249000005.jpg76 can be called the directional difference. If the curvature of point P in Figure 1-v is representative of the vehicle's travel curvature, then the curvature during a left turn is represented by a positive value (+), and the curvature during a right turn is represented by a negative value (-). Thus, a positive directional difference indicates that the vehicle's travel curvature needs to be increased, and the opposite indicates that it needs to be decreased. The requirement for the direction of travel is actually a requirement for the vehicle's travel curvature, but for cycling, it is sufficient to show whether the requirement increases or decreases without considering and calculating the actual magnitude of the travel curvature. The travel curvature is overall Because it is proportional to the fluctuation of JPEG2026517249000006.jpg76, the requirement for change in driving curvature is... This can be represented by the value (α0) of JPEG2026517249000007.jpg76.

[0013] Adjustment of the vehicle's curvature (Within a certain period) The change in vehicle angular velocity ω is the integral of the vehicle angular acceleration ω'. Therefore, if the angular acceleration (referring here to its absolute value) exceeds a certain value over a long period, it will cause a rapid change in angular velocity, which can easily lead to loss of control of the vehicle or rollover. In other words, as shown in Figure 1-v, OF must either oscillate (rapidly) around OP, or the angle it makes with OP must be relatively small. Consequently, the direction of the relative resultant force acting on the vehicle must change spatially in the same way as the vehicle and be synchronized overall (over a long period of time) (the average position of OF must be close to OP). In this way, by rotating OP and OF together, it is possible to adjust the vehicle's curvature (direction of travel). When the directional difference is positive, ω can be adjusted to a range of positive set values, that is, the vehicle rotates counterclockwise at a speed within that range. For example, after ω reaches a set value, efforts can be made to control ω' to 0, so that the vehicle rotates counterclockwise at a relatively constant speed. At this time, OF and OP coincide relatively and rotate synchronously. The adjustment of the direction of OF is the result of adjusting vector OS, and the change in OS is the result of a change in α. In this way, as the vehicle body is controlled to rotate counterclockwise, α and JPEG2026517249000008.jpg76 gradually increases, When JPEG2026517249000009.jpg76 matches α0, this stage of control is complete. Similarly, α0 If the value is less than JPEG2026517249000010.jpg76, the vehicle body is controlled to rotate clockwise, and this continues until the values ​​match. The vehicle body rotation speed ω should be set based on the vehicle's (relevant) driving conditions. Different vehicle speeds require different vehicle body rotation speeds (angular velocities) to change the same curvature; that is, different values ​​of ω are required to adjust the same curvature within the same period. Also, the magnitude of the directional difference (referring here to the magnitude of its absolute value, and so on) indicates the urgency of changing the direction of travel. Therefore, vehicle speed and the magnitude of the directional difference can be used as the primary basis for setting the target value (ideal value) of ω. The setting of the vehicle body rotation speed can also be adjusted in conjunction with information such as the vehicle's rocking state, changes in wind force, slipperiness of the road surface, and the movement of personnel and goods on board, thereby improving safety. Due to the presence of uncertainties, the control results often fluctuate up and down around the target value. Therefore, an acceptable range (feasible variable interval) can be set as the acceptable range for the control value based on the specific driving conditions of the vehicle. The target value of ω' can be set based on the difference between the current vehicle's ω and the set value of ω, and the set value of ω' is set to be proportional to the magnitude of this difference. Furthermore, by taking into account the rotational inertia of the steering wheels, fluctuations in related variables can be reduced, achieving better control effectiveness. Since the actual control value of ω' also fluctuates around its set value, the same logic can be used to set its tolerance. The magnitude of the directional difference and the difference between the vehicle's rotation state and the set value can be used as indicators for judging the vehicle's driving state (e.g., balance of a bicycle). If ω and ω' exceed the tolerance range (the difference between the actual control value and the set value is too large), or if the directional difference is too large, it means that the control has failed. In practical applications, ω' and ω change very rapidly. Generally, unless α0 changes abruptly or uncontrollable factors become large, JPEG2026517249000011.jpg76 approaches α0 very quickly, and adjustments to the required curvature of the vehicle's movement can be completed relatively quickly. In Figure 2-iii, external forces cause large deviations of ω and ω' from the ideal values ​​of the vehicle, and in the process of adjusting these variable values... It can also be considered that a situation has occurred where JPEG2026517249000012.jpg76 is greater than α0. At this time (which can be considered starting from point C), the system controls the vehicle based on this directional difference and begins to rotate it clockwise. That is, it controls ω' to decrease ω to a negative value, As JPEG2026517249000013.jpg76 approaches α0, ω' and ω are adjusted to approach zero. This example shows that even when α0 (required driving curvature) is always constant, there are fluctuations (to varying degrees) in α and ω. Due to the rotational inertia of the steering wheels and the vehicle body, rapidly vibrating the steering wheels (causing α to fluctuate back and forth around a constant value) is undesirable because it is risky (difficult to stabilize ω), and also leads to high vehicle wear and energy consumption. A safer solution is to control the vehicle's angular acceleration within a smaller range. This slows down the adjustment of changes in ω and directional differences, but makes it easier to keep the vehicle in a relatively stable control state, and the fluctuation of α in this state is also relatively small.

[0014] Measurement of vehicle angular velocity and related variables By attaching a gyro sensor (such as an angular velocity sensor) to the vehicle body, the vehicle's angular velocity can be measured, and the vehicle's angular acceleration can be calculated. The vehicle's angular velocity (referred to here as the target value) is the rotational speed around the contact point axis of the center of gravity plane and cannot usually be measured directly. A rigid plane rotating in sync with the center of gravity plane can be selected as the measurement plane, and its rotational speed in the relevant direction can be measured as a reference value. For example, in Figure 1-i, it is possible to select to measure the rotational speed around CD of the vehicle body plane JCD. While the bicycle is in motion, rotation around the directional axis of the steering wheel and related accessories, the operation of the vehicle's damping system, differences in tire pressure, and the swaying of people and items on board can all cause a relative shift in the center of gravity. Changes in the angle between the wheel surface and the ground also cause the contact point to shift left or right around the center line of the outer edge of the wheel. These factors tend to cause a difference between the target value and the reference value. These errors can be measured based on a specific vehicle type under different driving conditions to obtain a more accurate vehicle angular velocity value. If the gyro sensor can measure the angle change of the vehicle body surface in its own direction (such as the angle change of CD on surface CDJ in Figure 1-i), it is useful for acquiring the vehicle's oscillation state. Measurement and control of α can be performed by a servo mechanism, and there are various options for inputting α0 to the computer and measuring the vehicle speed, which will not be described in further detail here.

[0015] Single-wheel or two-wheel control system From the above analysis, it can be concluded that this type of vehicle can employ not only a system where the front wheels are the directional wheels, but also a system where the rear wheels are the directional wheels to adjust the vehicle's angular acceleration, or a system where the front and rear wheels rotate together for control. In any of these systems, it is sufficient that the rotation of the steering wheels (or wheels) can change the force on the contact point axis (or the vehicle's curvature). As shown in Figure 1-i, if JD is the pivot axis of the rear wheel, then a system in which the rear wheel surface rotates around JD, or a system in which the front and rear wheels rotate in coordination around JC and JD respectively, can also be used. Using two-wheel joint control significantly improves safety. This is because the probability of two independent systems failing simultaneously is extremely low, and if a problem occurs in one steering wheel system, the other system can maintain control until the vehicle is safely stopped, significantly reducing the accident rate. Two-wheel control also increases the flexibility and precision of control. In single-wheel control, in some cases While situations may arise where the difference between JPEG2026517249000014.jpg76 and α0 widens first, the two-wheeled scheme better avoids this situation and can respond more quickly to the demands for directional control. The two-wheeled control scheme may need to consider the different effects on the vehicle's curvature when the angles between the two wheel surfaces and the body surface change. As shown in Figure 1-i, when the magnitudes of ∠JCD and ∠JDC are different, even if the angles between the front and rear wheel surfaces and the body surface are the same magnitude (except when both are zero), the vehicle's curvature affected by each will be different, and this requires relevant measurements based on the specific vehicle type (see the proportionality constant λ mentioned above; it is necessary to know the λ corresponding to each of the two wheels and their ratio).

[0016] The impact of fluctuations in other factors such as vehicle speed and countermeasures If the vehicle's curvature (or α) is not zero, the vehicle's speed can be changed and the vehicle's angular acceleration can be adjusted, but changes in speed are related to factors such as driving requirements and safety, and should be controlled by the driver, and the machine should not normally intervene actively. However, in some cases, for example, if the driver wants to rapidly change the curvature ("sharp turn"), it is possible to change the vehicle's speed. The difference between 76 and α0 appears as a sharp increase, and in normal control, the time it takes for 76 to reach α0 becomes longer, and the driver's turning request cannot be promptly responded to. In this situation, considering the method of reducing the vehicle speed, the rapid adjustment of the driving direction of the vehicle can be assisted to be completed. Of course, this control method can also be set as an option that the user can set by himself. As described above, there is also inertia in the rotational movement of the steering wheel, and a certain amount of time is required for the variation of α. To cope with the variation of the vehicle body angular acceleration associated with the vehicle speed change, based on the user's speed adjustment command, α can be adjusted in advance before the vehicle speed actually changes to respond, and thereby the rotational state of the vehicle body can be better adjusted. If the relative variation situation of the physical entities carried by the vehicle such as the human body and articles can be detected and the influence of such changes can be predicted, it is also possible to control α to respond in advance. If the changes in related factors such as terrain and wind force can be predicted, they can also be added to the reference content of the control.

Brief Description of the Drawings

[0017] [Figure 1] It is an analysis diagram of related elements involved in the operation of a bicycle. [Figure 2] It is an analysis diagram of the gyro effect affecting the operation of a bicycle and a trend diagram of related variables when controlling the operation of a bicycle.

Modes for Carrying Out the Invention

[0018] Modes for Carrying Out the Invention In this specification, specific embodiments and precautions for each process have already been given, so here only a selective and brief description of these contents will be provided. The rotational speed (denoted by ω) of the bicycle frame around the contact point axis is measured by a gyro sensor, and the angular acceleration (denoted by ω') is calculated from it. The rotation angle (denoted by α) of the bicycle's steering wheel is measured and controlled using a servo mechanism, and ω' is controlled by controlling the change in α. The average value of α over a certain historical period ( The direction of travel (represented by JPEG2026517249000017.jpg76) is considered the direction of travel, and the difference between the requested direction (represented by α0) and the direction of travel (α0 - JPEG2026517249000018.jpg76) is called directional difference. Based on directional difference information and factors such as vehicle speed, target values ​​for ω and ω' are set, and then α is controlled so that ω approaches the target value and the directional difference is eliminated. In short, by controlling α to control ω', controlling ω' to control ω, and controlling ω to approach its set value, Ensure that JPEG2026517249000019.jpg76 constantly converges to α0. The difference between the vehicle's rotational state (ω and ω') and their set values, as well as the magnitude of the directional difference, can be used to judge the relative balance (stability, safety, etc.) of the vehicle's operation.

Claims

1. A method for driving a bicycle-type vehicle according to a direction request under automatic control, The axis of rotation is the straight line determined by the contact points of the front and rear wheels with the road surface. The relative rotational motion variables of the vehicle body with respect to the axis of rotation are measured, and calculations are performed based on these, A control request for the variable is set in combination with a request to adjust the direction of travel. A method characterized by achieving the requirement by controlling the change in the steering angle of the directional wheels.

2. In the method according to claim 1, A method characterized in that the aforementioned direction of travel is not calculated by the steering angle of the directional wheels or the current value of the vehicle's curvature, but by the average value of the variable within a certain historical period or within one change cycle.

3. In the method according to claim 1, The method is characterized in that, with respect to the control requests, the request for the direction of rotation of the vehicle body is determined by the sign of the direction difference, and the request for the rotational speed of the vehicle body is determined by the operating state of the vehicle.

4. In the method according to claim 1, The method for measuring and calculating the relative rotational motion variables of the vehicle body with respect to the rotation axis is characterized by measuring the angular velocity within these variables using a gyro sensor and calculating the angular acceleration based on this.

5. In the method according to claim 1, A method for controlling the change in the steering angle of the aforementioned directional wheels, characterized in that the directional wheels may be the front wheels of the vehicle, the rear wheels, or a coordinated operation mode of the front wheels and rear wheels.

6. In the method according to claim 1, The method is characterized in that the quality of the implementation process is determined by the magnitude of the absolute value of the directional difference and the difference between the vehicle body rotation variable and the set value.

7. In the method according to claim 4, The method is characterized in that, with respect to the angular acceleration, the setting of the control target is determined by the difference between the angular velocity and the set value, and if information that affects the change can be predicted, the relevant control can be coordinated in advance.

8. In the method according to claim 1, Regarding the control of the aforementioned variables, when a request to change the direction of travel is relatively urgent, it is possible to selectively use vehicle speed adjustment as an auxiliary means. By installing a gyroscopic mechanism with its rotation axis perpendicular to the ground contact axis and rotating it as needed, the difficulty of this control task can be reduced. A method for determining the magnitude of the change in steering angle required to change angular acceleration is characterized by considering that the magnitude is inversely proportional to the square of the vehicle speed, as well as considering the influence of related factors including the vehicle body structure, the angle between the center of gravity plane and the ground, and the gyroscopic effect.

9. In the method according to claim 3, The operating conditions of the aforementioned vehicle include not only the absolute values ​​of vehicle speed and directional difference, but also conditions such as the vehicle's oscillation state, changes in wind force, slipperiness of the road surface, and vibration of the mounted object. This method is characterized in that information regarding the vehicle's oscillation state can be obtained by measuring the change in angle of the vehicle body in the plane on which it is positioned using a gyro sensor.

10. In the method of claim 2, The method is characterized in that, with respect to the steering angle and driving curvature, the value is set to zero when the vehicle is moving straight, the opposite sign is used to represent the difference in the direction the vehicle is turning, and the magnitude of the value is determined by the difference from when the vehicle is moving straight.

11. A front and rear wheeled vehicle, having a function to perform balance management and direction adjustment in automatic mode, The axis of rotation is the straight line determined by the contact points of the front and rear wheels. The relative angular velocity of the vehicle body with respect to the rotation axis is measured and calculated, The angular velocity is controlled by adjusting the steering angle of the directional wheels. When no adjustment of the direction of travel is required, the angular velocity is controlled to continuously approach zero. A front and rear wheeled vehicle characterized by its ability to control the angular velocity to maintain it within a certain range when adjustment of the direction of travel is necessary.

12. In the vehicle according to claim 11, The aforementioned direction of travel refers to the overall direction of movement of the vehicle, and is characterized in that it can be expressed as the average value of the variable within a certain historical period or within one change cycle, ignoring the effects of short-term or small fluctuations in the steering angle or the vehicle's curvature.

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