Self-balancing vehicle control method and self-balancing vehicle

Abstract

The present invention relates to a method for controlling a self-balancing vehicle with a braking procedure and a self-balancing vehicle, comprising an inertial sensor combined with a base frame (2) of the vehicle (1) and configured to detect an inclination angle (α) of said base frame (2) relative to a horizontal axis (X), and a control unit configured to drive the vehicle based on a virtual reference inclination angle (β) when the inclination angle (α) detected by the inertial sensor differs from a predetermined reference inclination angle (γ) due to a front or rear imbalance of a user of the vehicle.

Description

[Technical Field]

[0001] The present invention relates to self-balancing vehicles, such as a Segway® two-wheeler, a unicycle, or other similar single-axle vehicles, and to methods for controlling these self-balancing vehicles. [Background technology]

[0002] In recent years, self-balancing vehicles have become popular due to their practicality and ease of use, as well as the ease with which they facilitate personal transportation in urban areas. The operation of these single-axle vehicles is known and is typically based on a control system connected to an inertial sensor that can detect the balance of the vehicle while the user is riding. When the inertial sensor detects that the user has tilted from equilibrium, the control system accelerates the wheels of the single-axle vehicle in proportion to and in the same direction as the user's tilt. Similarly, when the user reduces their tilt and returns their center of gravity to equilibrium, the control system decelerates the wheels. In this way, the user can move forward simply by tilting their weight on the vehicle in the direction they want to move.

[0003] For example, a well-known type of self-balancing vehicle includes a seat mounted on a platform with two side wheels, with two electric motors independently driving the two wheels. A control system is connected to the two wheels and includes inertial sensors capable of detecting the balance of the machine. When the user's forward or backward lean changes, the control system responds by applying torque to the motors to return the seat to a state of equilibrium. Under normal conditions, the two wheels are free to move, so the applied torque corresponds to a positive or negative acceleration, respectively. This type of device is equipped with handlebars and / or control levers, through which the control system can perform steering actions by utilizing the differential torque between the two motors. There are also seatless types of devices that have handlebars or levers for steering. In either case, the user can shift their weight forward or backward with their chest movement to increase or decrease their forward speed.

[0004] In special circumstances, such as an imminent danger or an unexpected obstacle, it may be necessary to rapidly slow down the speed of a moving vehicle. Because this movement is generated by a change in the equilibrium state of the overall balance of the vehicle with the user on board, mechanical braking of both wheels is not possible, as this would cause a loss of equilibrium and the user may fall.

[0005] For example, as described in Patent Documents 1, 2, and 3, vehicles are known that include control systems that can process response actions such as emergency acceleration, deceleration, and braking based on information and situation data from inertial sensors or other sensing systems integrated into the vehicle. However, such systems do not provide a means for manually controlling emergency braking, so a user cannot manually apply the brakes even if they sense a danger.

[0006] Patent Document 4 discloses an invention relating to a coaxial two-wheel vehicle having two wheels arranged on the same axle center line, and a control method thereof. In particular, Patent Document 4 discloses an invention relating to a coaxial two-wheel vehicle on which a person rides and operates the vehicle, and a control method thereof. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP5182127B2 [Patent Document 2] CN108466668A [Patent Document 3] WO2010116640A1 [Patent Document 4] US2010038163A1 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, the technical problem posed and solved by the present invention is to provide a control method for a self-balancing vehicle and a self-balancing vehicle that can overcome the drawbacks of the prior art. In particular, an object of the present invention is to provide a method for controlling a self-balancing vehicle that can increase the safety of a user while moving, such as when it is necessary to quickly stop the self-balancing vehicle. [Means for solving the problem]

[0009] Such a problem is solved by a control method according to claim 1 and a vehicle according to claim 9. Preferred and further features of the invention are the subject of the dependent claims. The present invention offers several related advantages, the main one being improved control of the vehicle while moving and thus increased safety for the user: in fact, the control method and system of the present invention allows the user of a self-balancing vehicle to deal with a sudden danger or obstacle without having to suddenly shift his or her weight, but simply triggering the braking procedure by pressure on the brake members.

[0010] In fact, the control method and system of the present invention allows a user of a self-balancing vehicle to brake the self-balancing vehicle in a manner similar to most common mechanically braked vehicles, such as bicycles, motorcycles, and other vehicles. However, unlike the latter, the braking of the present invention is not performed using conventional mechanical systems, such as drum brakes, disc brakes, etc., but rather by modifying at least a predefined, predetermined reference tilt angle that the vehicle uses to define its equilibrium position (and that the user sets at startup). As a result, braking is immediate and intuitive, making it suitable for even inexperienced users.

[0011] In practice, such a reference tilt angle is replaced by a virtual reference tilt angle having a value smaller than the predetermined reference tilt angle, so that the motor of the self-balancing vehicle is driven based on the virtual reference tilt angle to perform or contribute to performing a braking action rather than an accelerating action. Such a virtual reference tilt angle may be varied depending on the speed of the self-balancing vehicle and the gradient of the road surface on which the vehicle is traveling. This allows the braking effect to be adjusted according to the situation of the self-balancing vehicle itself. Other advantages, features and uses of the present invention will become apparent from the following detailed description of some embodiments thereof, given for illustrative and non-limiting purposes. [Brief explanation of the drawings]

[0012] [Figure 1] 1A-1C are side views of a self-balancing vehicle in angular positions for one step of the control method of the present invention. [Figure 2] 10A-10C are side views of the self-balancing vehicle at different angular positions during other steps of the control method of the present invention. [Figure 3] 10A-10C are side views of the self-balancing vehicle at different angular positions during other steps of the control method of the present invention. [Figure 4] 1 is an axonometric view of a vehicle that is the subject of the control method of the present invention; [Figure 5] 1 is a front view showing a detailed configuration example of a vehicle to which a control method of the present invention is applied; DETAILED DESCRIPTION OF THE INVENTION

[0013] Various embodiments and modifications of the present invention will now be described with reference to the drawings, in which like reference numerals denote like elements throughout the drawings. The thicknesses and curvatures shown in the figures should be understood as examples only and are not necessarily drawn to scale. In the detailed description below, additional embodiments and additional modifications to the embodiments and modifications already described will be described by limiting the description to the differences from the already described contents. Furthermore, the different embodiments and variants described below may be used in combination where compatible.

[0014] First, the control method according to the present invention will be described below with reference to the drawings. The control method of the present invention is suitable for a self-balancing vehicle 1 (the meaning of which is known to those skilled in the art) comprising a base frame 2 and inertial sensors such as gyroscopes and accelerometers (not shown but known to those skilled in the art) associated with the base frame 2. Such an inertial sensor is configured to detect the tilt angle α of the base frame 2 relative to a horizontal axis X (horizontal is the direction perpendicular to the direction of gravity). An angle of 0° defines a perfectly horizontal tilt angle of the base frame 2, a positive tilt angle corresponds to a counterclockwise tilt of the base frame 2, and a negative tilt angle corresponds to a clockwise tilt of the base frame 2. In particular, if the base frame 2 tilts forward, the tilt angle is positive, and if it tilts backward, the tilt angle is negative. It should be noted that clockwise and counterclockwise directions mentioned herein refer to the accompanying Figures 1 to 3.

[0015] The vehicle 1 is equipped with at least one motor (not shown in the drawings but well known to those skilled in the art) for driving and moving the vehicle itself, and also includes a control device connected to the inertial sensors and the motor. In each of the figures, a vehicle 1 is shown for illustrative purposes only, with two wheels coupled with two independent electric motors, and further includes a seat 3 that allows a user to move while seated, and a control handlebar 4. The control handlebars 4 are fixed to the base frame 2 , and the seat 3 is also fixed to the base frame 2 .

[0016] In each drawing, for illustrative purposes only, a vehicle 1 is shown having two wheels 20, a seat 3 and control handlebars 4 that allow a user to move while seated. However, it should be noted that a self-balancing vehicle 1 without a seat also falls within the scope of protection of the present invention. Furthermore, a self-balancing vehicle having only one wheel, and therefore only one electric motor coupled to that wheel, also falls within the scope of protection of the present invention.

[0017] FIG. 5 shows details of the control handlebar 4 of the vehicle 1. This is an example and not a limitation. The handlebar 4 is equipped with a control monitor 6 configured to display all information useful to the user, such as speed, remaining battery power, and other vehicle status information (along with other useful information). The illustrated handlebar 4 is equipped with buttons 8 configured to operate various functions, such as beeping (honking) and turning lights on / off. As will be described later, the handlebar 4 is also equipped with a brake member 5 that can be operated by the user. Furthermore, the handlebar 4 can be equipped with a handlebar 7 that can be opened and closed. The control handlebar 4 is not excluded in different embodiments.

[0018] As mentioned above, the vehicle 1 preferably comprises two independent motors, each connected to a respective wheel 20, and both motors connected to a control unit. Using the control handlebars 4, a user can apply differential torque to the two motors to steer the vehicle 1 in a desired direction. The control method according to the invention makes it possible to detect the tilt angle α of the base frame 2 relative to the horizontal axis X using an inertial sensor. With reference to the drawings, An angle of 0° defines a perfectly horizontal tilt angle of the base frame 2 as shown in FIG. A positive angle of the tilt angle α corresponds to a counterclockwise tilt of the base frame 2 as shown in FIG. A negative tilt angle α corresponds to a clockwise tilt of the base frame 2, as shown in FIG.

[0019] 1 to 3 show an orthogonal system XV in which the X axis is the horizontal axis and the V axis is the vertical axis. According to the control method of the present invention, a control unit (not shown in the drawings for simplicity) is used to compare the detected tilt angle α of the base frame with a predefined reference tilt angle γ (hereinafter sometimes abbreviated as "angle γ"). This reference tilt angle γ is usually set to +5° to -5°, preferably +3° to -3°. For ease of explanation and as an example, each drawing shows a case where the predefined reference tilt angle γ is -1° (see FIG. 1).

[0020] According to the method of the present invention, the control unit drives the vehicle 1 to move if the detected tilt angle α differs from a predefined reference tilt angle γ. This usually occurs because the user of the vehicle 1 loses balance forward or backward. In other words, the predefined reference tilt angle γ defines an equilibrium state. When the user loses balance, i.e., shifts their center of gravity from the equilibrium state, the motors (two motors in this embodiment) are driven by the control unit, which processes the data detected by the inertial sensors.

[0021] If the value of the tilt angle α of the base frame measured in the counterclockwise direction is greater than the defined reference tilt angle γ, the motor performs an acceleration operation. Similarly, if the value of the tilt angle α measured in the counterclockwise direction is smaller than the defined reference tilt angle γ, the motor will brake. According to the invention, it is possible to manually initiate a braking procedure at least when the detected tilt angle α of the base frame is greater than a predetermined reference tilt angle γ. Indeed, the method of the invention allows the user to brake the vehicle without necessarily tilting it backwards, as is the case with self-balancing vehicles of the known art.

[0022] In the braking procedure of the present invention, the control unit replaces the defined, predetermined reference tilt angle γ with a virtual reference tilt angle β (hereinafter sometimes abbreviated as "angle β") that is smaller than this angle γ, and drives the motor based on this virtual reference tilt angle β to perform braking. In other words, the control unit changes the vehicle's balance reference in the direction opposite to the direction of movement, which is simply indicated in the drawing by arrow D. In fact, when the difference between the detected base frame tilt angle α and the virtual reference tilt angle β with respect to the predefined reference tilt angle γ increases, a sudden braking torque is generated to brake the vehicle 1.

[0023] In practice, when the braking procedure is activated, the vehicle 1 reaches the virtual reference tilt angle β after a very rapid transient time, and then preferably steadily decelerates to a near standstill, after which the virtual reference tilt angle β is again replaced by the predetermined reference tilt angle γ. At this point, the vehicle 1 is stopped in the equilibrium position set by the user. The transition from the virtual reference tilt angle β to the predefined reference tilt angle γ can be performed according to various algorithms depending on the user's preferences.

[0024] The virtual reference tilt angle β is preferably between −2° and −15°, and preferably −10°, as shown in Figure 1. Within these values, the brake is particularly effective and safe for the user. According to the present invention, during the braking procedure, the conversion from angle γ to angle β can be effectively performed in a time interval of, for example, the order of 1 / 10th of a second to 1 second, thereby reducing the shock sensation associated with braking and enabling a more comfortable deceleration for the user.

[0025] The control method of the present invention can effectively replace the virtual reference tilt angle β with the defined reference tilt angle γ in a stepwise manner during the deceleration phase of the vehicle 1 after the braking procedure is initiated. In other words, during the deceleration phase after the braking operation is initiated, as the speed of the vehicle 1 decreases, the braking effect adapts to the vehicle's driving situation, thereby ensuring the user's equilibrium state. In practice, as the vehicle 1 decelerates, the virtual reference tilt angle β gradually approaches the defined reference tilt angle γ. In general, angle β can be set based on user preference to provide more or less braking effect depending on the user's driving preferences.

[0026] Preferably, the virtual reference tilt angle β can be variable depending on the vehicle speed. Indeed, the control unit can process data from the inertial sensor to estimate the speed and recalculate the angle β accordingly. In particular, if the speed is lower than a predefined speed value, the angle β can be adjusted to soften the braking action. Thus, the present invention has the advantage of being able to maintain the user's balance when the user activates a braking procedure under certain speed conditions.

[0027] As an example, assume that the value of the predefined reference tilt angle γ is set to −1° and the user offset defines the tilt angle α of the base frame to be 8° (see FIG. 2 ), the vehicle 1 is moving forward at a speed of approximately 15 km / h, and the predefined speed value is set to 10 km / h. In this situation, the angle β is fixed at -10°. If the vehicle slows down below a certain speed value, the control unit recalculates the angle β. For example, if the vehicle slows down to 8 km / h, the angle β is recalculated to -5°. In this way, when the braking procedure is triggered, there is no risk that the base frame 2 will tip backwards and cause the user to lose their sense of balance. The braking effect is therefore adjusted to the actual driving situation of the vehicle when the braking procedure is triggered. Alternatively, the braking effect may be maintained until the vehicle has fully decelerated and then the brakes are released. In this case, the vehicle may move slightly backwards.

[0028] Preferably, angle β is variable depending on the inclination of the support surface of vehicle 1. In this way, angle β can adapt to any changes in inclination that vehicle 1 may encounter while traveling. In fact, the control unit can process data from the inertial sensor to estimate the inclination and recalculate angle β accordingly. In particular, if the inclination is greater than a predefined reference inclination angle, angle β is modified to weaken the braking action. This has the advantage of ensuring the user's equilibrium when the user initiates a braking procedure under certain inclination conditions.

[0029] In the above example, assume that the value of the predefined reference inclination angle γ is set to -1° and the user offset defines the inclination angle α to be 8°. If the vehicle 1 is traveling on a route with zero gradient, the predefined gradient value is set to 4°. In this situation, the angle β is fixed at -10°. If the gradient increases / decreases, the method can cause the control unit to recalculate the angle β. For example, if the route travels uphill at +10°, the angle β is recalculated to -4°. In this way, when a braking procedure is initiated, there is no risk of the base frame 2 tipping backwards and impairing the user's sense of balance. The braking effect is therefore adjusted to the actual driving situation of the vehicle when the braking procedure is activated. If the vehicle is traveling downhill at a -10° angle, the angle β is recalculated to -14°, which biases the balance of the base frame 2 backwards, thereby improving the controllability of the vehicle 1 downhill.

[0030] Preferably, the braking procedure is operated by at least one user-operable brake member 5. When the user wishes to start the braking operation, the user can manually operate the brake member 5. The brake member 5 is connected to the control unit and is configured to start the braking operation at least when the detected tilt angle α of the base frame is greater than a predetermined reference tilt angle γ.

[0031] The user can effectively vary the virtual reference tilt angle β depending on the pressure applied to the brake member 5. This state of the brake member 5 is detected by the control unit and transferred to the motor control board via a communication channel in the form of a numerical field representing the percentage of braking action requested by the user. This has the advantage that the user has the feeling of control over the magnitude and action of the braking action in proportion to the pressure applied to the brake member, similar to mechanical brakes commonly used on other vehicles such as bicycles and motorcycles. The value of the virtual reference tilt angle β can actually be dynamically changed based on the pressure applied by the user to the brake member 5. In this case, the brake member 5 is preferably a lever, for example of the type used on motorcycles. However, in the example shown in accompanying FIG. 3, the braking member 5 is a button.

[0032] A more detailed description of the operation of the control method according to an embodiment of the present invention is provided below. The vehicle 1 described in the present application is equipped with an inertial sensor configured to detect the tilt angle α of the base frame 2 of the vehicle 1 relative to a horizontal axis X, with an angle of 0° defining a perfect horizontal tilt angle of the base frame 2.

[0033] In the accompanying drawings, typically, a positive value of the tilt angle α corresponds to a counterclockwise tilt of the base frame 2, and a negative value of the tilt angle α corresponds to a clockwise tilt of the base frame 2, with the movement direction D being from right to left. This means that when the base frame 2 is tilted forward with respect to the traveling direction, the tilt angle α is positive, and when it is tilted backward with respect to the traveling direction, the tilt angle α is negative.

[0034] The control unit compares the detected tilt angle α of the base frame with a predetermined reference tilt angle γ (for example, −1° in the embodiment shown in FIG. 1) which represents the equilibrium tilt and stable running shape of the vehicle 1 . The tilt angle α of the vehicle 1 during movement (i.e., the tilt angle of the base frame 2 of the vehicle 1) is monitored and controlled by a control unit, and the detected tilt angle α is always related to the predetermined reference tilt angle γ. A change in the tilt angle α during movement typically occurs when the user of the vehicle 1 loses balance forward or backward, causing the user's center of gravity to shift from the equilibrium state, and the motor is activated by the control unit based on data detected by the inertial sensor.

[0035] The operation of the method according to an embodiment of the present invention will now be described in more detail. The vehicle 1 described in this application is equipped with an inertial sensor configured to detect the tilt angle α of the base frame 2 of the vehicle 1 relative to a horizontal axis X, an angle of 0° defining a perfectly horizontal tilt angle of the base frame 2. Typically, a positive value of the tilt angle α corresponds to a counterclockwise tilt of the base frame 2, and a negative value of the tilt angle α corresponds to a clockwise tilt of the base frame 2, and the movement direction D is from right to left according to the accompanying drawings.

[0036] That is, when the base frame 2 is tilted forward with respect to the direction of movement, the tilt angle α is positive, and when the base frame 2 is tilted backward with respect to the direction of movement, the tilt angle α is negative. The control unit compares the detected tilt angle α with a predetermined reference tilt angle γ, which represents the equilibrium tilt and stable driving configuration of the vehicle 1, for example equal to −1° (in the embodiment shown in FIG. 1).

[0037] The tilt angle α of the vehicle 1 while it is moving (i.e., the tilt angle of the base frame 2 of the vehicle 1) is monitored and controlled by the control unit, and the detected tilt angle α is always associated with the predetermined reference tilt angle γ. Typically, this occurs when the user of the vehicle 1 loses balance forward or backward, causing the user to shift their center of gravity from equilibrium, and the motors are driven by the control unit based on data detected by the inertial sensors.

[0038] According to the present invention, in the initial operation phase, the vehicle can have a positive value of the tilt angle α of the movement direction D associated with the acceleration phase of the vehicle, until the desired movement speed is reached, according to an appropriate movement of the center of gravity by the user taking into account the equilibrium configuration (see, for example, Figure 1).

[0039] According to the manual initiation of the braking procedure of the present invention, when at least the tilt angle α is greater than the reference tilt angle γ, the control unit almost instantly (within 0.1 to 1 second) decides to replace the predetermined reference tilt angle γ with a virtual reference tilt angle β having a value smaller than the value of the predetermined reference tilt angle γ. As a result, the tilt angle α of the base frame 2 of the vehicle 1 increases in the opposite direction (in this case, clockwise) to the predetermined reference tilt angle γ relative to the direction of travel D due to the action of the vehicle self-balancing control.

[0040] This means that the reference tilt angle γ almost instantly increases to a negative value, becoming the virtual reference tilt angle β, causing the vehicle's balance reference to change in the direction opposite to the direction of travel D, resulting in an almost instantaneous "lean back" effect on the base frame 2 of the vehicle 1. In this way, the relative value (i.e., the value obtained by the control device of vehicle 1) of the tilt angle α of the base frame to the reference tilt angle γ (here, angle β) increases, and the relative value to the previous balance axis represented by the reference tilt angle γ changes from α + γ to α + β.

[0041] This is interpreted by the control unit of the vehicle 1 as a strong (potentially dangerous) tilt of the base frame 2 of the vehicle 1, which causes the control unit to "lean back" (reducing the tilt angle α towards the virtual reference tilt angle β) and converge to a (virtual) equilibrium configuration, thus initiating a braking phase in line with the self-balancing principle of the vehicle 1. This causes the motor to decelerate rapidly, the value of the base frame tilt angle α to converge quickly to the value of the virtual reference tilt angle β, and at the end of the braking operation, the vehicle 1 stabilizes back to the initial value of the reference tilt angle γ.

[0042] The duration of this braking phase depends on how hard and long you press the brake button, and how slow your new target speed is compared to the speed you were traveling at when the brake button was pressed. It is important to consider that the virtual reference tilt angle β depends not only on the vehicle speed but also on the inclination of the road surface on which the same vehicle is traveling, in order to take into account external driving conditions and user preferences regarding the desired driving experience. [Example]

[0043] It is assumed that the vehicle is traveling at approximately 15 km / h, the reference tilt angle γ is set to −1°, and the tilt angle α of the user (base frame) while traveling is set to +8°. It is assumed that the predefined speed value is set to 10 km / h, and at this speed the control unit fixes the virtual reference tilt angle β to −10°. If the vehicle is traveling at 15 km / h with a tilt angle α of +8° and the user presses the brake button, the control unit changes the reference tilt angle γ from the set value (-1°) to a virtual reference tilt angle β (-10°) (the value of this angle β represents a temporary value of the reference tilt angle γ). This means that the relative value of the base frame tilt angle α and the new reference tilt angle γ changes almost instantaneously from (+8°-(-1°)=+9°) to (+8°-(-10°)=+18°).

[0044] The control unit reacts to this virtual increase in the value of the tilt angle α with a braking action, changing the speed from 15 km / h to 10 km / h and simultaneously changing the base frame tilt angle α from +8° to -10°, thus exhibiting γ = β (a "leaning back" effect). Then, at the end of the braking phase, the tilt angle α gradually stabilizes and converges to the initial setting value of the reference tilt angle γ, where the base frame tilt angle α is equal to -1°.

[0045] If the user needs to further reduce the speed (for example, from 10 km / h to 8 km / h), from the moment the brake button is pressed, the control unit recalculates the virtual reference tilt angle β as -5°, and the reference tilt angle γ is almost instantly changed by the control unit from -1° to -5°. As a result, the control unit drives the motor to reduce the vehicle speed from 10 km / h to 8 km / h, and at the same time, the tilt angle α of the base frame almost instantly converges to the virtual reference angle β value equal to -5° (a "leaning back" effect), and after the end of this braking operation, the vehicle is stabilized and the tilt angle α converges to the initial setting value of the reference tilt angle γ equal to -1°.

[0046] Referring again to the drawings, a self-balancing vehicle 1 according to the present invention is disclosed as follows. In particular, but not exclusively, according to a preferred embodiment, the vehicle comprises a base frame 2 of a self-balancing vehicle 1 and an inertial sensor coupled to the base frame 2. As already explained, the inertial sensor, not shown in the drawings, is configured to detect a tilt angle α (hereinafter also referred to as angle α) of the base frame 2 relative to a horizontal axis X. As mentioned above, an angle of 0° defines a perfectly horizontal tilt angle of the base frame 2, a positive angle of the angle α corresponds to a counterclockwise tilt of the base frame 2, and a negative angle of the angle α corresponds to a clockwise tilt of the base frame 2.

[0047] The vehicle 1 further comprises at least one motor configured to move and / or brake the vehicle 1. As already mentioned, the vehicle may preferably comprise two independent motors connected to each wheel 20, as in the above example. In this case, the number of wheels is therefore two, but in other embodiments the number of wheels may be one without departing from the scope of protection of the present invention.

[0048] The vehicle 1 includes a control unit connected to an inertial sensor and a motor of the vehicle 1. The control unit is configured to drive the vehicle 1 to move when a detected tilt angle α of the base frame, which is detected when a user of the vehicle 1 loses balance forward or backward, differs from a predefined reference tilt angle γ (hereinafter, sometimes referred to as angle γ). Depending on whether the detected angle α has a value greater than or less than angle γ when measured counterclockwise, the motor performs an accelerating or braking operation.

[0049] Finally, the vehicle includes a manually operated brake unit operatively connected to the control unit, the brake unit configured to initiate the braking procedure described above at least when the angle α is greater than the angle γ, i.e., the control unit replaces the predetermined reference tilt angle γ with a virtual reference tilt angle β having a value smaller than the predetermined reference tilt angle γ, and drives the motor to perform the braking operation based on the virtual reference tilt angle β.

[0050] The vehicle 1 also includes a control handlebar 4 for the vehicle 1, which has a control monitor 6 configured to display all information useful to the user, such as speed, remaining battery power, and other vehicle status information (among other useful information). The handlebar 4 is equipped with buttons 8 for, for example, sounding a beep (horn) and turning lights on and off. The handlebar 4 also includes a brake member 5 that can be operated by the user, as will be described below. Additionally, the handlebar 4 may be equipped with a retractable handlebar 7.

[0051] The braking unit preferably comprises one or more braking members 5 that are accessible to the user and configured to start and stop the braking procedure. With reference to Figures 4 and 5, in a preferred (but not limited to) embodiment, the braking member 5 comprises two actuation units, i.e. buttons, that allow the user to start / stop the braking procedure. These buttons are located on both sides of the handlebar 4 so that the user can operate them with either hand at any time. In another embodiment, the brake member 5 can be of the lever type. A combination of the two above embodiments is not excluded, nor are other alternative embodiments excluded. Finally, the vehicle 1 comprises a seat 3 integrated with the base frame 2 .

[0052] Although the braking procedure described so far has been one in which braking is performed by changing only the predetermined reference tilt angle γ as the procedure for braking the vehicle 1, the present invention does not exclude the possibility that this procedure may involve a braking procedure of the vehicle that is electronically forcibly controlled by a control unit.

[0053] The present invention has been described with reference to preferred embodiments. Each technical feature realized in the preferred embodiments described herein for illustrative purposes only can also be advantageously combined with other features in a manner different from that described, thereby realizing additional embodiments that also relate to the same inventive core. It is therefore to be understood that there may be other embodiments that relate to the same inventive core, as defined by the scope of protection of the claims set forth hereinafter. [Explanation of symbols]

[0054] 1. Self-balancing vehicle 2 base frame 3 seats 4 Control Handlebars 5 Brake member 6 Control Monitor 7. Handlebars 8 Buttons 20 wheels α Base frame tilt angle β Virtual reference tilt angle γ is a defined reference tilt angle D Moving direction X horizontal axis

Claims

1. A method for controlling a self-balancing vehicle (1), comprising: The vehicle comprises a base frame (2), an inertial sensor combined with the base frame (2), at least one motor configured to drive the vehicle (1), and a control unit connected to the inertial sensor and the motor, detecting an inclination angle (α) of the base frame (2) relative to a horizontal axis (X) and a direction of movement D by the inertial sensor; comparing the detected tilt angle (α) with a predefined reference tilt angle (γ) by the control unit; driving the vehicle (1) by the control unit when the front or rear balance of the user of the vehicle (1) is lost and the detected tilt angle (α) of the base frame is different from the predefined reference tilt angle (γ); at least when the detected tilt angle (α) is greater than the predetermined reference tilt angle (γ), the control unit replaces the predetermined reference tilt angle (γ) with a virtual reference tilt angle (β) having a value smaller than the predetermined reference tilt angle (γ); In the step of detecting the tilt angle (α) of the base frame (2) by the inertial sensor, an angle of 0° defines a perfectly horizontal tilt angle of the base frame (2), a positive angle of the tilt angle corresponds to a counterclockwise tilt of the base frame (2), and a negative angle of the tilt angle corresponds to a clockwise tilt of the base frame (2); In the step of driving the vehicle (1) by the control unit, the motor performs an accelerating operation or a braking operation depending on whether the detected tilt angle (α) has a value greater than the predetermined reference tilt angle (γ) when measured in a counterclockwise direction or a value smaller than the predetermined reference tilt angle (γ); wherein, in the step of manually initiating the braking procedure, the motor is driven based on the virtual reference tilt angle (β) to exert or contribute to exerting a braking effect.

2. 2. The control method for a self-balancing vehicle according to claim 1, wherein the predetermined reference tilt angle (γ) is between +5° and −5°, and the virtual reference tilt angle (β) is between −2° and −15°.

3. 3. The method for controlling a self-balancing vehicle according to claim 1, wherein the replacement of the predetermined reference tilt angle (γ) with the virtual reference tilt angle (β) during the braking procedure is performed at specific time intervals of the order of 1 / 10th of a second to 1 second.

4. 3. The method for controlling a self-balancing vehicle according to claim 1, wherein the virtual reference tilt angle (β) is variable as a function of the speed of the vehicle, and when the speed is lower than a predetermined speed value, the virtual reference tilt angle (β) is modified to reduce the braking action.

5. 3. The method for controlling a self-balancing vehicle according to claim 1, wherein the virtual reference tilt angle (β) is gradually replaced by the predetermined tilt angle (γ) when the vehicle is decelerating during the braking procedure.

6. 3. A method for controlling a self-balancing vehicle according to claim 1 or 2, characterized in that the virtual reference tilt angle (β) is variable as a function of the inclination of the support surface of the vehicle (1), and if the inclination is greater than a predetermined value, the virtual reference tilt angle (β) is modified to reduce the braking effect.

7. 3. A method for controlling a self-balancing vehicle according to claim 1 or 2, characterized in that the initiation of the braking procedure is operated by at least one brake member (5) accessible to the user.

8. 8. A method for controlling a self-balancing vehicle according to claim 7, characterized in that the virtual reference tilt angle (β) is variable as a function of the pressure applied by the user to the braking member (5).

9. A self-balancing vehicle (1), Base frame (2), an inertial sensor combined with the base frame (2) and configured to detect the tilt angle (α) of the base frame (2) relative to a horizontal axis (X); at least one motor configured to drive and / or brake the vehicle (1); a control unit connected to the inertial sensor and the at least one motor; and a manually actuated brake unit operatively connected to the control unit for manually initiating a braking procedure; In the inertial sensor, An angle of 0° defines a perfectly horizontal tilt angle of the base frame (2), a positive angle of the tilt angle corresponds to a counterclockwise tilt of the base frame (2), and a negative angle corresponds to a clockwise tilt of the base frame (2); the control unit is configured to drive the vehicle (1) when the detected tilt angle (α) differs from the predetermined reference tilt angle (γ) due to a front or rear imbalance of a user of the vehicle (1); the motor performs an accelerating operation or a braking operation depending on whether the detected tilt angle (α) has a value greater than the predetermined reference tilt angle (γ) when measured in a counterclockwise direction or a value smaller than the predetermined reference tilt angle (γ); the manually actuated brake unit is configured to manually initiate the braking procedure at least when the detected tilt angle (α) is greater than the predetermined reference tilt angle (γ), and the control unit is configured to replace the predetermined reference tilt angle (γ) with a virtual reference tilt angle (β) having a value smaller than the predetermined reference tilt angle (γ).

10. 10. A self-balancing vehicle according to claim 9, characterized in that the braking unit comprises one or more braking members (5) accessible to the user and adapted to start and stop the braking procedure.

11. A self-balancing vehicle according to claim 10, characterized in that the one or more braking members (5) are of the button type.

12. Self-balancing vehicle according to claim 10, characterized in that the one or more braking members (5) are of the lever type.

13. 11. A self-balancing vehicle according to claim 10, characterized in that it comprises a handlebar (4) constrained to the base frame (2), the handlebar (4) comprising the one or more brake members (5).

14. 11. The self-balancing vehicle according to claim 9 or 10, comprising at least one wheel (20), wherein the at least one motor drives the at least one wheel (20) to move.

15. 11. A self-balancing vehicle according to claim 9 or 10, characterized in that it comprises at least one seat (3) integrated with the base frame (2).

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