Wheeled vehicle with tilt control

Abstract

A wheeled vehicle (10) capable of adjusting its lateral tilt. In a preferred aspect, the vehicle (10) includes a seat (28) for supporting an occupant and a chassis (18) carrying the seat. A steered wheel (12) is carried by the chassis and is operably coupled to steering means (30, 34) for turning the steered wheel (12) to effect steering of the vehicle (10). A left wheel support arm (66) carries a left wheel (14) and is pivotally coupled to the chassis (18) such that pivotal movement of the left wheel support arm (66) provides up and down movement of the left wheel (12) relative to the chassis (18). A right wheel support arm (68) carries a right wheel (16) and is pivotally coupled to the chassis (18) for independent movement from the left wheel support arm (66) such that pivotal movement of the right wheel support arm (68) provides up and down movement of the right wheel (16) relative to the chassis (18). A left control line (76) is routed from a left tether (79) on the left wheel support arm (66) to an actuator (84) carried by the chassis (18) such that upward movement of the left wheel (14) relative to the chassis is limited by the control line (18). A right control line (82) is routed from a right tether (78) on the right wheel support arm (68) to the actuator (84) such that upward movement of the right wheel (16) relative to the chassis (18) is limited by the right control line (82). The actuator (84) is operable in a first direction to pay out the left control line (76) while taking in the right control line (82) to thereby allow the left wheel (14) to move upward relative to the chassis (18) and the right wheel (16) to move downward relative to the chassis (18) to thereby tilt the vehicle (10) to the left. The actuator (84) is operable in a second direction to pay out the right control line (82) while taking in the left control line (76) to thereby allow the right wheel (16) to move upward relative to the chassis (18) and the left wheel (14) to move downward relative to the chassis (18) to thereby tilt the vehicle (10) to the right.

Description

Technical Field

[0001] This invention relates to a motorized wheeled vehicle with an active tilt control mechanism.

[0002] One application of this invention relates to mobile scooters, such as those used by people who may have difficulty walking due to age or frailty. Mobile scooters are known in form. They are typically electric, moderately long and wide four-wheeled vehicles, making them well-suited for use on roads and paths alongside other pedestrians. Mobile scooters generally lack an enclosed cabin, having a low-profile chassis housing the battery and electronics, and a vertical pole for supporting the user's seat. Steering is provided via a simple handlebar mechanism that controls a pair of steering front wheels. Some existing mobile scooters have a three-wheeled layout. Background Technology

[0003] Uneven or sloping terrain can pose problems for mobile scooters and their riders. Due to their moderate width, mobile scooters can become somewhat unstable when traversing steep inclines, and even if they manage to remain upright on such surfaces, the resulting tilt can be unpleasant for the user. Even urban environments present challenges in this regard. For example, consider a side-wheel movement from the road surface down a curb. This can cause a conventional vehicle to tilt to one side and remain tilted, potentially causing the user anxiety or even physical injury.

[0004] Therefore, there is a need to provide a low-speed vehicle, which may be a mobile scooter, capable of controlling its tilt angle when traversing uneven terrain. Such a vehicle is designed to maintain its chassis and its rider in a substantially upright position (at least sideways, i.e., without tilting significantly to the left or right), regardless of the slope or unevenness of the ground below.

[0005] Vehicles with three (or in some cases four) ground wheels, and whose chassis is tilted relative to the ground in some way, are known in various forms. Several documents in this broad general category will be discussed below. Some are similar to bicycles or motorcycles because they allow the vehicle to tilt, as determined by dynamic conditions, without requiring any power mechanism to directly adjust the vehicle's tilt. Primarily, tilting mechanisms, whether passive or active, serve as a way to improve the vehicle's dynamics when cornering, thereby aiding its dynamic stability and its road-holding at speeds by enabling the vehicle to tilt or actively tilt into a corner.

[0006] The problems arising from these two aspects, for example, from low-speed vehicles primarily used on sidewalks rather than those used more rapidly on roads, are somewhat different. In this paper, weight is a significant factor, and the relatively complex mechanisms used in many prior art vehicles present problems in this regard. In the case of relatively simple electrically propelled vehicles, providing, for example, a hydraulic system would be complex and expensive. A mechanism is needed that can actively adjust the vehicle's tilt, is simple in construction, can be configured in a way that does not excessively contribute to the overall weight of the vehicle, and is preferably easy to repair and maintain.

[0007] While not all embodiments of the invention require the ability to fold or otherwise shrink into a compact structure, this is a desirable feature in some examples where the ability to place the scooter in, for example, the trunk of a motor vehicle can be very advantageous.

[0008] Beyond mobile scooters, another challenge associated with tilt-wheeled vehicles is that control modes suited to low speeds may not be appropriate at higher speeds. Maintaining balance and stability at low speeds is expected and can be challenging. At higher speeds, balance may be less of an issue, especially since riders are able to dynamically balance the vehicle, and a more proactive and / or dynamic operating mode may be required. Some vehicles, belonging to the prior art and discussed below, are able to lock their wheels in an "upright" configuration when stationary and can release the wheels, allowing the vehicle to tilt freely once in motion. However, this is only a partial solution to the aforementioned problems.

[0009] Examples of tilting vehicles that belong to the prior art are given in the following literature.

[0010] Prince's US4887829A specifically addresses "off-road riding" and solves problems related to the dynamic balance of a three-wheeled vehicle during off-road driving. The document discloses a three-wheeled vehicle with each rear wheel mounted on a corresponding rocker arm. Each rocker arm is connected to its respective end via a shock absorber, and the rocker arm itself is pivotally connected to the vehicle's frame. This arrangement appears designed to allow the rider to lean into corners, similar to what is possible for a rider on a two-wheeled vehicle such as a motorcycle. This does not imply that the rocker arm arrangement should be automatically actuated in any way.

[0011] Miller's US5116069A discloses a three-wheeled vehicle proposed as an improvement on a conventional four-wheeled motor vehicle, which uses a slightly complex hydraulic system to tilt the vehicle into a turn in order to maintain the load on the inner wheel and thus avoid the tendency of such a vehicle to sideslip due to overload on the outer wheel during a turn. Each of the two rear wheels of the vehicle is equipped with a corresponding hydraulic actuator to raise and lower the rear wheel, and has a mechanical control device for the hydraulic system that utilizes a pair of heavy-duty suspensions acting on valves in the hydraulic system. Whether or not this is an actual way to control the tilting of a motor vehicle traveling on the road, it is a mechanically complex device.

[0012] Calleja Vidal's EP0606191A1 relates to a three-wheeled vehicle in which the rear wheel is supported on a corresponding sway fork to allow the rear wheel to rise and fall, and is connected by a device including levers, each of which is connected at its end to a corresponding sway fork via a corresponding link. The "balancer" device can be locked by some form of mechanical brake, for example when the vehicle is stationary, but the document does not suggest actively actuating the "balancer" device for automatic control.

[0013] Ernst's DE4423859A1 describes a vehicle with a balancing mechanism that uses a corresponding hydraulic actuator for each of a pair of wheels, the actuator having a pressure chamber directly connected by a conduit, such that one pressure chamber moves relative to the other. Another embodiment uses a chain guided around the four wheels. In either case, it is clear that the vehicle's tilt is caused by changes in the driver's weight.

[0014] Benelli SpA's EP1346907A describes a suspension system for a double-swing-axle wheel used in a tilting vehicle. This suspension features a slightly complex lever mechanism to coordinate the movement of the two wheels, enabling a "riding style typically used in motorcycles." The tilting action of this suspension is lockable, thus keeping the vehicle stable, particularly when stationary; however, the document does not teach the dynamic control of the tilting mechanism.

[0015] Matthies' US7343997B illustrates a form of three-wheeled motorcycle with a double wishbone rear suspension featuring a full set of shock absorbers. The upper ends of these units are connected to a lever mechanism including links connected to actuators. This arrangement allows the vehicle to tilt via the upward / downward movement of the shock absorbers and the wheels to which they are connected, and the actuators can be controlled to tilt the motorcycle in the direction of cornering. A similar mechanism is disclosed in Matthies' US9487234.

[0016] Steinhilber's WO2008 / 052539A1 discloses a three-wheeled vehicle with a tilting mechanism that uses a pair of pivotally mounted trailing arms to support the respective rear wheels. In some embodiments, these trailing arms extend forward so that they can be actuated by the rider's feet, thus giving the rider control over the tilt of the vehicle. A brief suggestion is that this pedal mechanism can be electrically or hydraulically assisted.

[0017] Steinhilber's DE102006052041A discloses a tilting three-wheeled vehicle in which a tilting mechanism associated with the rear wheels is combined with a steering mechanism acting on the front wheels. To enable increased tilting at higher speeds, a separate hydraulic unit is provided to provide speed-dependent adjustment of the vehicle's tilt.

[0018] Toyota JIDOSHA Kabushiki Kaisha's US20080290618A details a three-wheeled vehicle with a complex suspension system, in which coordinated control is applied to the steering angle, the angles of left and right tilt, and the angles of forward and backward tilt, but electrically controlled devices are used on the two rear wheels. This control system appears capable of independently controlling the two wheels.

[0019] Bayerische Motoren Werke Aktiengesellschaft's DE102009042662 describes a three-wheeled vehicle in which paired wheels are driven to propel the vehicle, and a hydraulic system acts on the paired wheels to actively control the vehicle's tilt angle.

[0020] Pallanca et al.'s FR2995869 provides another example of a tilting vehicle in which the two rear wheels are connected by a lever mechanism, the vehicle tilts freely as a two-wheeled vehicle while in motion, and a locking mechanism is provided to selectively lock the tilting device, for example, when stationary.

[0021] Koi Moto Sdn Bhd’s WO2017099576 describes several different wheeled vehicles and multiple mechanisms, some of which have four wheels and others take the form of a three-wheeled children’s scooter. These mechanisms allow the track width of a pair of wheels to vary with their tilt angle.

[0022] Doerksen's US10501119B discloses and describes a vehicle that uses a four-bar linkage to tilt a pair of wheels together with the vehicle's central chassis. In some embodiments, a gear transmission controls the tilting action. Summary of the Invention

[0023] The present invention provides a vehicle according to the appended independent claims. Attached Figure Description

[0024] Specific embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0025] Figure 1 This is a view of the vehicle embodying the invention from the front of the vehicle to one side of the vehicle;

[0026] Figure 2 This is another view of the vehicle from above, one side, and the rear.

[0027] Figure 3 It is a side view of the vehicle;

[0028] Figure 4 This is a rear view of the vehicle;

[0029] Figure 5 This is a detailed view of the rear of the vehicle as seen from one side;

[0030] Figure 6 It is a bottom view of the vehicle;

[0031] Figure 7 This is a slightly schematic illustration of the releasable coupling used in the second embodiment of the vehicle;

[0032] Figure 8 This is a detailed view of the horizontal control mechanism used in some embodiments of the invention; and

[0033] Figure 9A , 9B 9C is a simplified illustration of a vehicle showing the effect of the horizontal control mechanism. Detailed Implementation

[0034] This embodiment is an electric vehicle 10 with a three-wheeled layout, having a single front wheel 12, a left rear wheel 14, and a right rear wheel 16. Conversely, the invention can be implemented with a three-wheeled layout having two wheels at the front and one wheel at the rear. The wheel can be referred to as a "ground wheel," and of course, the wheel travels on the ground beneath the vehicle 10.

[0035] Vehicle 10 has a simple chassis 18, which in this example includes a curved, front-to-back extension structure with a generally horizontally extending front chassis member 20 extending rearward toward a sloping chassis member 22. Near the upper end of the sloping chassis member 22, the sloping chassis member 22 includes fittings 24 for accommodating a rod 26 of a seat 28. In this embodiment, the seat 28 is a simple saddle-shaped device without a backrest, but other forms are also possible. Specifically, when vehicle 10 is used as a mobile scooter, vehicle 10 can be configured to provide more support to the user, for example, through a backrest and / or armrests and / or headrests. Fittings 24 allow the seat 28 to be raised and lowered according to the user's needs. In this embodiment, fittings 24 include a pair of rod-engaging brackets secured by threaded fasteners, which clamp the rods when tightened and release the clamping rods when loosened to allow the clamping rods to slide.

[0036] At the front of the vehicle 10 is a generally upright steering column 30, the lower end of which carries the front wheel 12 via a fork-like member 32. The length of the steering column is telescopically adjustable to allow for adjustment of the height of the handle 34. For this purpose, the steering column includes an upper column portion 30a slidably housed within a lower column portion 30b. A releasable locking device is provided to prevent longitudinal and rotational movement of the two column portions 30a, 30b relative to each other during use; however, suitable devices are well known to those skilled in the art and will not be described here.

[0037] The steering column 30 is connected to the chassis 18 via a steering bearing member 36 carried on a bearing bracket 38. The steering bearing member 36 includes a tubular member through which the steering column 30 passes. In this embodiment, the tubular member forms a sliding bearing for the steering column 30, but in other embodiments, the tubular member may include, for example, a ball bearing or a needle bearing. In this example, the bearing bracket 38 includes an upright front panel 40 that carries the steering bearing member 36. On the left and right sides of the front panel 40, the front panel 40 carries a left wing and a right wing 42, which extend downward to be located on either side of the front chassis member 20. The wing 42 forms a pivot attachment between the front chassis member 20 and the bearing bracket 38. For this purpose, a pivot pin passes through alignment holes in the wing 42 and the front chassis member 20. Figure 1The end of the pivot pin is seen at position 44. To lock the bearing bracket 38 (and the steering column 30 supported thereon) in its vertical orientation for use, the left and right locking pins 46 each pass through holes in their respective wings 42 into corresponding complementary holes in the front chassis component 20. The locking pins can be retracted to allow the steering bracket 38 and steering column 30 to pivot relative to the chassis 18.

[0038] The handle 34 carries a brake controller in the form of a brake lever 48, used to control the braking devices acting on the wheels to brake the vehicle. The range of suitable braking devices is well known to a skilled mechanical engineer and is not detailed here, except that, as can be seen in the accompanying drawings, the brake cable 50 is guided from the brake lever 48 to the steering column 30. The handle 34 also includes a user-operable speed controller 52 with a lever 54 whose position indicates the user's speed or power demand, for input to the propulsion control system.

[0039] Each of the front chassis component 20 and the tilting chassis component 22 includes a hollow tubular portion (specifically, they have a square or rectangular hollow cross-section) that forms an internal chassis space 56 for accommodating the vehicle's working components. In this embodiment, the chassis side panels 58 are removable to provide access to these working components.

[0040] Vehicle 10 is electrically driven by the front wheels 12. Electric propulsion is particularly suitable for vehicles of this type, but in principle, other forms of propulsion, including any suitable form of internal combustion engine, may also be used in other vehicles implementing the invention. Power for vehicle propulsion and for other functions described below is provided by battery 60 and transmitted via electric motor drive 62 to an electric motor assembly housed in the wheel hub 64 of the front wheels 12. Battery 60 and motor drive 62 are housed in the internal chassis space 56.

[0041] It must be understood that, although details of a particular chassis construction and steering system have been described herein, the invention is not in any sense limited to implementation in vehicles having this type of chassis or steering.

[0042] The left wheel 14 rests on the lower end of a left wheel support arm 66, which is pivotally connected to the chassis 18 at its upper end. Similarly, the right wheel 16 rests on the lower end of a right wheel support arm 68, which is pivotally connected to the chassis 18 at its upper end. In this embodiment, the left wheel support arm 66 and the right wheel support arm 68 rotate about a common pivot axis defined by a pivot rod 70 extending through a pivot bracket 72 supported on the tilting chassis member 22 and through the corresponding carriers (not shown) in the left wheel support arm 66 and the right wheel support arm 68. Thus, this pivoting mechanism allows the left wheel support arm 66 and the right wheel support arm 68 to rotate independently of each other. In operation, the range of angles through which the wheel support arms rotate is small, less than 90 degrees. Clearly, when either wheel support arm 66 or 68 rotates, its corresponding wheel 14 or 16 rises or falls relative to the chassis 18, thereby changing the tilt of the vehicle 10. The wheel support arms 66 and 68 may be referred to as trailing arms because the wheel support arms 66 and 68 extend rearward (and downward) from the pivot axis defined by the pivot rod 70.

[0043] The left and right wheels each rotate about their respective axle axes, which are defined by those axes. Figure 1 One of the ends of the corresponding wheel axle is shown at position 74. In this embodiment, the wheel axis is parallel to the pivot axis of the wheel support arms 66, 68, so that rotation of the wheel support arms 66, 68 does not change the orientation of the wheel axle relative to the chassis 18. The left and right wheel support arms are always tilted downwards during use, which means that the axis of the wheel supported on the arm is lower than the pivot axis 70 about which the arm rotates.

[0044] Wheel support arms 66 and 68 do not need to pivot about the same axis. The pivot axis of one wheel support arm may be tilted relative to the pivot axis of the other wheel support arm, and / or the pivot axis of the wheel support arm may be offset.

[0045] A tilt control mechanism is provided that controls the angular position of the left wheel support arm 66 and the right wheel support arm 68 (i.e., the tilt control mechanism controls the rotational movement of the left and right wheel support arms about a pivot axis defined by the pivot rod 70), thereby controlling the tilt of the vehicle 10. The term "tilt" as used herein refers to the angle formed between the chassis 18 and a vertical plane extending in the longitudinal direction of the vehicle. In other words, "tilt" is the angle at which the vehicle tilts to the left or right. As can be clearly seen from the accompanying drawings, raising the left wheel 14 will cause the vehicle to tilt to the left. Moving the right wheel downward will have the same effect. If one wheel is raised a certain distance while the other wheel is lowered by the same distance, the vehicle will tilt with minimal change in its height.

[0046] In this embodiment, the tilt control mechanism includes control lines 76 and 82. As used herein, the term "control line" refers to long, flexible components capable of maintaining tensile loads without excessive strain, and should be understood to include, but is not limited to, lines, cables, ropes, and chains. In this embodiment, control lines 76 and 82 are cables made of ultra-high molecular weight polyethylene (UHMWPE), a registered trademark. They are available for sale and are chosen for their high stiffness under tensile loads. Nevertheless, control lines 76 and 82 can be made from a variety of different materials.

[0047] For details, please refer to the following: Figure 5 The right control line 76 connects to the right wheel support arm 68 at the right arm tether 78, which is located on the portion of the arm away from its pivot axis 70. The right control line is guided from the right arm tether 78 to a chassis-mounted line guide 80, which in this example is supported on the inclined chassis member 22.

[0048] If observe Figure 5 Understandably, a triangle is formed by (a) the right arm tether 78, (b) the chassis-mounted line guide 80, and (c) the pivot axis 70. The vertex (its highest point) of this triangle is formed by the pivot axis 70 of the right wheel support arm 68. The right portion 76 of the control line forms the base (its lowest edge) of the triangle. The interior angle at the vertex of the triangle is the angle between the right wheel support arm 68 and the chassis 18, and determines the height of the right wheel 16 relative to the chassis 18. When the right control line is released or pulled in by the linear actuator 84, the right control line changes the length of the base of the triangle, and thus changes the aforementioned apex angle, and thus changes the height of the right wheel 16.

[0049] The right control line 76 supports the weight of the vehicle 10 and is thus kept taut during operation. Clearly, the weight borne by the right wheel 16 tends to cause that wheel to move upwards relative to the chassis 18, and this tendency is prevented by the tension in the right control lines 76 and 82. If the length of the right control line 76 from the chassis-mounted guide 80 to the right arm tether 78 is shortened, the right wheel will move downwards relative to the chassis 18; or equivalently, the right side of the chassis 18 will rise as the right wheel 16 rests on the ground. If the same portion of the right control line 76 is released, the right side of the chassis moves downwards.

[0050] The control cable device is the same for the left wheel support arm 66. The left control cable 82 extends from the left arm tether 79 to the chassis-mounted cable guide 80 to control the rotational movement of the left wheel support arm 66.

[0051] The tilt control mechanism includes actuators acting on control lines 76 and 82. In this embodiment, the actuator is a linear actuator 84 mounted on chassis 18, and more specifically, on tilt chassis member 22. In this particular embodiment, the linear actuator 84 includes a carrier 86 having a carrier wheel 88, which engages with a track 90. ​​An electric actuator motor 92 drives a lead screw 94 threadedly engaged with the carrier 86, such that rotation of the lead screw moves the carrier 86 along the track 90 in a controllable manner. The electric motor is electrically driven by an actuator motor controller 96.

[0052] In this embodiment, control lines 76 and 82 are secured to the carrier 86 at the carrier tether 98. The left control line 76 and right control line 82 can be formed by a single continuous line or by two separate lines, both leading to the carrier tether 98. The right control line 76 is guided directly from the carrier 86 to the chassis-mounted line guide 80, and from the line guide 80 to the right arm tether 78. The left control line 82 is guided from the carrier 86 to the second line guide 100 (located at the end of the linear actuator 84 opposite the chassis-mounted line guide 80), and from the second line guide via the chassis-mounted line guide 80 to the left arm tether 79. As a result, when the actuator 84 operates in the first direction, the left control line 82 is released and the right control line 76 is pulled in. When the actuator 84 moves in the opposite direction, the left control line 82 is pulled in and the right control line 76 is released.

[0053] In this embodiment, the line guides 80 and 100 are formed by pulleys. The chassis-mounted line guide includes a left pulley 102 and a right pulley 104, which respectively accommodate the left control line 76 and the right control line 82, allowing the control lines to move in opposite directions. However, any suitable form of line guide can be used instead. For example, a common cable guide can be used.

[0054] The tilt control mechanism shown causes the left wheel support arm 66 and the right wheel support arm 68 to move simultaneously and in opposite directions; that is, if one arm moves upward, the other arm moves downward. To tilt the vehicle to the left, the carrier 86 moves upward. The left control line 82 is released, causing the left wheel support arm 66 to rise relative to the chassis 18. The right control line 76 is pulled in, causing the right wheel support arm 68 to move downward relative to the chassis 18. To tilt the vehicle to the right, the carrier moves downward.

[0055] Vehicle 10 can be folded very easily for transport and storage. The left wheel support arm 66 and right wheel support arm 68 are pivoted freely and aligned to fold approximately parallel to the inclined chassis member 18, reducing the vehicle's weight, thus minimizing volume. The retractable locking pin 46 allows the steering column 30 to pivot toward the chassis, and the steering column can also be telescopically folded, providing a compact overall configuration.

[0056] The tilting action of vehicle 10 is controlled by electronic controller 106 in response to several different parameters. In this embodiment, electronic controller 106 is a digitally programmable device. Controller 106 includes sensors responsive to vehicle conditions or coupled to sensors responsive to vehicle conditions. In particular, controller 106 includes an inertial measurement unit (IMU). This is a well-known form of sensor array familiar to those skilled in the art and typically includes gyroscopes sensitive to rotation about three non-parallel axes and accelerometers sensitive to acceleration along the three non-parallel axes. Based on the IMU sensor outputs, the controller can determine the current tilt of the vehicle relative to the vertical direction (i.e., relative to the local gravitational field). Controller 106 can also receive inputs from one or more sensors in response to the angular position of one or more of the wheel support arms 66, 68 (or some other part of the tilt control mechanism whose position corresponds to the arm position, such as carrier 86). The controller can receive input representing vehicle speed, which can be obtained from the detected wheel rotation speed. The controller can also receive input representing the vehicle steering angle or radius, which can be obtained from the detected angular position of steering column 30.

[0057] Using its sensor inputs, the controller 106 can implement multiple control strategies.

[0058] In a particularly suitable first control strategy when vehicle 10 operates at low speeds, such as when vehicle 10 is in the form of an ineffective vehicle, the tilt control mechanism operates with the goal of always keeping chassis 18 vertical. That is, regardless of changes in the terrain on which vehicle 10 moves, the chassis 18 must be prevented from tilting to the left or right. For this purpose, a feedback loop is implemented, where the sensed tilt angle of chassis 18 is the control variable. The controller responds to any deviation by operating the tilt control mechanism in a closed-loop manner to reduce any detected deviation of the chassis tilt angle relative to the vertical direction. Conventional PID (proportional, integral, derivative) control strategies can be used for this purpose.

[0059] Prototype vehicle testing has demonstrated that the vehicle shown in the attached diagram provides a very stable and consistent upright orientation for the chassis 18 and seats 28, despite significant variations in ground inclination traversed by the vehicle 10. This provides a significantly improved experience for users, especially the elderly or infirm.

[0060] Nevertheless, the present invention can also be implemented in vehicles with higher speeds, where it is desirable to provide dynamic adjustment of the chassis 18 relative to the vertical direction, especially during cornering. At higher speeds, tilting the vehicle in the direction of cornering (i.e., tilting to the left when turning left, or tilting to the right when turning right) has many benefits. This helps to distribute the load more evenly between the left and right wheels, improves the vehicle's dynamic stability, and enhances user comfort.

[0061] In the second control strategy, the tilt control mechanism is operated to adjust the vehicle's tilt angle (relative to the vertical direction), but during steering, the vehicle tilts in the steering direction. This operating mode retains the advantage that the vehicle remains laterally upright despite changes in terrain, but adds dynamic balance during steering.

[0062] Another embodiment of the invention will now be described, which enables different forms of control over the tilt of the vehicle 10.

[0063] In the above embodiment, the tilt control mechanism is always operational when the vehicle is in use. The configuration of the tilt mechanism and the positions of the left wheel 14 and the right wheel 16 are always controlled by the controller 106.

[0064] However, many vehicles capable of tilting lack such automatic control over their tilt angles, which are dynamically determined by multiple factors. Examples include two-wheeled vehicles such as bicycles and motorcycles. The tilting and balance maintenance of such vehicles occur due to dynamic factors including steering angle and subsequent rate of lateral acceleration, vehicle speed, user position (the user can laterally shift their center of gravity), and rotational forces generated by the rotating wheels. The prior art listed above includes examples of three-wheeled vehicles, which, while allowing the vehicle to tilt in response to these forces, resemble motorcycles without using mechanisms for actively controlling vehicle tilting.

[0065] A familiar problem associated with cyclists and motorcyclists is that vehicles become less stable at low speeds. Experienced riders are able to maintain dynamic balance quite well. When stationary at road junctions, very few people can keep the vehicle stable and upright without placing their feet on the ground. It is common to observe motorcyclists dragging one or both feet at low speeds as an aid to balance.

[0066] The embodiments of the invention described below provide the benefits of automatic balance control in a first state (preferably a low-speed state) and dynamic balance in a second state (preferably a high-speed state). This is achieved by actively controlling the tilt angle via a tilt control mechanism in the first state and allowing the vehicle to tilt under the influence of dynamic factors in the second state. By way of example only and not limitation, the first state can be carried out from a standstill to a speed of approximately 10 km / h (6 mph), and then the second state can be selected. Once in the second state, the vehicle can return to the low-speed state when its speed decreases to approximately 6 km / h (3 mph).

[0067] For this purpose, a releasable coupling device 112 is provided to selectively connect the actuator 84 to or disconnect the actuator 84 from the tilt control mechanism. In this embodiment, the releasable coupling device is integrated into the support tether 98. In a first state, the releasable coupling device 112 engages with control lines 76, 82, such that movement of the support 86 causes movement of the control lines 76, 82. In a second state, the releasable coupling device 112 allows the control lines to pass freely, thereby allowing the control lines 76, 82 and the tilt mechanism to move as a whole independently of the support 86 and the linear actuator 84.

[0068] The releasable coupling device can take any of a variety of forms commensurate with its function. This is merely an example. Figure 7 A releasable coupling device 112 is shown, having a housing 114 through which control lines 76, 82 pass and housing a first set of clamping jaws 116 and a second set of clamping jaws 118. The first set of clamping jaws 116 and the second set of clamping jaws 118 are oriented oppositely; that is, one set of clamping jaws is arranged to lock the control lines 76, 82 to prevent movement in one direction, while the other set is arranged to lock the control lines 76, 82 to prevent movement in the opposite direction, so that when both are engaged, the control lines 76, 82 are effectively coupled to the releasable coupling device 112. The clamping jaws 116, 118 are releasable. Pressure applied along arrow 120 causes the clamping jaws to release the control lines 76, 82. This pressure can be applied, for example, by a suitable cable arrangement (not shown).

[0069] In operation, when the vehicle is in the first state (typically stationary or moving at low speed), the releasable coupling device 112 engages to connect the tilting mechanism to the linear actuator 84, so that the vehicle tilting is automatically controlled by the controller 106. In the second state (typically at higher speeds), the releasable coupling device 112 disengages, and the vehicle tilts freely due to the dynamic forces acting upon it, without being regulated by the controller 106.

[0070] The transition from one state to another must be managed to some extent. In some embodiments, the user controls the transition via appropriate user-operable controls. Thus, the user decides whether to rely on automatic tilt controls or to balance the vehicle itself. In other embodiments, the controller 106 manages the transition from one state to another based on measured operating parameters, particularly speed, so that the vehicle automatically possesses the advantages of stability at low speeds and dynamic handling at high speeds. To ensure that the releasable coupling device 112 engages the control lines 76, 82 at appropriate points along its length and to provide a smooth transition to the first state, the controller 106 can be programmed to position the actuator 84 based on the current tilt angle of the vehicle 10 (established by sensors).

[0071] The aforementioned mechanism controls vehicle tilt by moving the left wheel support arm 66 and the right wheel support arm 68 in opposite phases, which minimizes any changes in the height of the seat 28 caused by the action of the tilt control mechanism. However, in other embodiments of the invention, a leveling control mechanism 122 is incorporated, which is used to move the left wheel support arm 66 and the right wheel support arm 68 in phase with each other (i.e., the two arms move simultaneously in the same direction via the leveling control mechanism 122).

[0072] Although a variety of different mechanisms can be used for this purpose, Figure 8 An example highly suitable for use in the vehicle 10 of the type described above is shown, representing a minor modification thereof. This type of tilt control mechanism 122 includes a second actuator 124 configured to simultaneously release and pull in the left control line 82 and the right control line 76. In this example, the second actuator 124 is a linear actuator carrying a pulley block 126, on which both the right control line 76 and the left control line 82 are guided. When the actuator 124 is driven to move the pulley block 126 upward, the effect is to pull out of the two control lines 76, 82 and move the left wheel 14 and the right wheel 16 downward relative to the chassis 18. When the actuator 124 is driven to move the pulley block 126 downward, the effect is to release the control lines 82, 76 and move the left and right wheels 14, 16 upward relative to the chassis 18.

[0073] from Figures 9A to 9C The effect of this level adjustment is understandable. At the normal level ( Figure 9A Seat 28 is at a mid-height position, and the vehicle is best configured for lateral stability. At a low level ( Figure 9B The height of seat 28 is lowered, and control lines 76 and 82 are lengthened. The center of gravity of the vehicle and the user is relatively low, and the wheelbase of vehicle 10 is extended, making the vehicle more stable in the longitudinal direction. This configuration can be used when traveling with a sharp tilt upwards or downwards. At a high level ( Figure 9C The seat height is increased by 28 degrees. This configuration may not be as stable as others, but it is designed to elevate the user. For example, this may be desirable during social interactions so that the user does not need to look steeply upwards at their companion during a conversation.

[0074] It is emphasized that the foregoing embodiments are presented by way of example and not limitation. Many variations can be made without departing from the scope of the invention as set forth in the appended claims. For example, the linear actuator 84 need not be electrically driven: it can be hydraulically driven instead. In a hydraulic system, disengagement of the actuator from the tilt control mechanism can be achieved by a valve device to allow fluid to flow freely into and out of the working chambers of the hydraulic piston and hydraulic cylinder device, such that the hydraulic actuator will move freely with the tilting motion of the vehicle 10 without being physically separated from the vehicle 10. A rotary actuator, such as an electric motor, can be used instead of a linear actuator, wherein control lines 76, 82 are guided, for example, around pulleys or gears, so that the rotary actuator can move the control lines, and in the second embodiment, a rotary clutch is used to engage / disengage the rotary actuator to the control lines 76, 82. The controller 106 has been depicted and described for the foregoing as a single unit, but it can take any suitable form. For example, the functionality of the controller can be split across multiple processors and / or multiple physical units. The controller can be a networked device that communicates with a remote server via a wide area network, such as a mobile phone network (cellular telephone network in American English).

Claims

1. A wheeled vehicle, comprising: A seat, used to support the passenger; The chassis supports the seats; Steering wheels, carried by the chassis and operably connected to a steering mechanism for rotating the steering wheels to steer the vehicle; A left wheel support arm carries the left wheel and is pivotally connected to the chassis, such that the pivoting motion of the left wheel support arm provides the vertical movement of the left wheel relative to the chassis; as well as The right wheel support arm carries the right wheel and is pivotally connected to the chassis so as to be able to move independently of the left wheel support arm, such that the pivoting movement of the right wheel support arm provides the up-and-down movement of the right wheel relative to the chassis. The wheeled vehicle is characterized in that it further comprises: The left control line includes a long and flexible member that can maintain tension. The left control line is guided from the left tether on the left wheel support arm to the actuator device, such that the upward movement of the left wheel relative to the chassis is limited by the tension of the left control line. A right control line, comprising a long and flexible member for maintaining tension, the right control line being guided from a right tether on the right wheel support arm to an actuator device such that the upward movement of the right wheel relative to the chassis is limited by the tension of the right control line; and An actuator device includes an actuator mounted on the chassis and acting on the left control line and the right control line, wherein: The actuator is operable in a first direction to release the left control line while simultaneously pulling in the right control line, thereby allowing the left wheel to move upward relative to the chassis and the right wheel to move downward relative to the chassis, thereby causing the vehicle to tilt to the left. The actuator is operable in a second direction to release the right control line while simultaneously pulling in the left control line, thereby allowing the right wheel to move upward relative to the chassis and the left wheel to move downward relative to the chassis, thus tilting the vehicle to the right.

2. The vehicle according to claim 1, wherein, The left control line and the right control line are part of a continuous control line.

3. The vehicle according to claim 1 or 2, wherein, The left wheel support arm is pivotally connected to the chassis. The left control line enters the actuator device via a line guide; The pivot, the left tether, and the line guide form an imaginary triangle, the vertex of which is the pivot, and the base of which is a path taken from the pivot to the line guide, such that pulling in the left control line reduces the interior angle at the vertex of the triangle, and releasing the left control line increases the interior angle at the vertex of the triangle.

4. The vehicle according to claim 1 or 2, wherein, The control line is a flexible component that can withstand tensile loads but not compressive loads.

5. The vehicle according to claim 1 or 2, wherein, The control line includes a rope, line, cord, or chain.

6. The vehicle according to claim 1 or 2, wherein, The actuator is a linear actuator having a carrier that can move back and forth along a linear path by a motor, the carrier being connected to the left control line and the right control line.

7. The vehicle according to claim 6, wherein, The left control line is guided away from the carrier along a first direction, the right control line is guided away from the carrier along a second direction, and the first direction and the second direction are opposite to each other.

8. The vehicle according to claim 1 or 2, wherein, The vehicle includes a motor or engine that is droopingly connected to at least one of the steering wheel, the left wheel, and the right wheel to propel the vehicle.

9. The vehicle according to claim 1 or 2, wherein, When the weight of the vehicle is reduced, the left wheel support arm and the right wheel support arm move freely downward relative to the chassis, thereby enabling the left wheel support arm and the right wheel support arm to be turned into a retracted configuration.

10. The vehicle according to claim 1 or 2, comprising a steering bearing member rotatably receiving a steering column, the steering wheels being mounted on the steering column.

11. The vehicle according to claim 10, wherein, The steering bearing component is connected to the chassis via a pivoting connection, the pivoting connection being provided with a releasable rotational locking device, the pivoting connection allowing the steering column to move between a used position and a retracted position, and the rotational locking device being configured to releasably lock the steering column in the used position.

12. The vehicle according to claim 1, comprising: An electronic controller is operatively coupled to the actuator; Multiple sensors are configured to sense operating parameters of the vehicle, including the lateral tilt of the vehicle relative to the vertical direction; The electronic controller is configured to control the actuator in response to the output of the sensor to adjust the tilt of the vehicle relative to the vertical direction.

13. The vehicle according to claim 12, wherein, The electronic controller is capable of operating in a first mode, in which it tends to keep the vehicle vertical despite changes in terrain.

14. The vehicle according to claim 13, wherein, The electronic controller is configured to achieve closed-loop control of vehicle tilt based on the sensed deviation between the vehicle's lateral tilt and the vertical direction.

15. The vehicle according to any one of claims 12 to 14, wherein, The electronic controller is capable of operating in a second mode, in which it adjusts the lateral tilt of the vehicle to compensate for changes in terrain and also tilts the vehicle in the steering direction.

16. The vehicle according to any one of claims 12-14, comprising a reversibly releasable coupling between the actuator and the control line, such that the vehicle can operate in the following state: (1) A first state in which the releasable coupling is engaged and lateral vehicle tilting is controlled by the electronic controller via the actuator; and (2) Second state, in which the releasable coupling is disengaged and the vehicle lateral tilt can vary independently of the actuator.

17. The vehicle according to claim 16, wherein, The releasable coupling is controlled by the electronic controller, which is configured to operate the vehicle in the first state in a low-speed range and in the second state in a high-speed range.

18. The vehicle according to claim 1 or 2, further comprising a leveling mechanism, wherein the leveling mechanism: It can be operated in a first direction to simultaneously release the left control line and the right control line, thereby causing the left wheel support arm and the right wheel support arm to move upward relative to the chassis; It can be operated in the second direction to simultaneously pull in the left control line and the right control line, thereby causing the left wheel support arm and the right wheel support arm to move downward relative to the chassis.

19. A steerable, power-driven wheeled vehicle, comprising: Chassis; At least one steering wheel, the steering motion of which controls the steering of the vehicle; The left wheel is capable of moving up and down relative to the chassis; The right wheel is capable of moving up and down relative to the chassis; A tilt control mechanism operably connects the left wheel and the right wheel such that when the left wheel moves upward relative to the chassis, the right wheel moves downward relative to the chassis, and when the left wheel moves downward relative to the chassis, the right wheel moves upward relative to the chassis. The tilt control mechanism includes a control line, which includes a rope, line, cord, or chain, and the rope, line, cord, or chain is tensioned to inhibit the upward movement of the left wheel and the right wheel relative to the chassis. An actuator is operatively connected to the control line via a reversible, releaseable coupling; Multiple sensors, in response to the lateral tilt of the vehicle; as well as A controller configured to receive the output of the sensor and control the actuator. The vehicle is configured to operate in a first state and a second state, wherein... In the first state, the releasable connector engages, making the actuator operably connected to the control line, and the controller adjusts the lateral tilt of the vehicle based on the output of the sensor via the actuator and the tilt control mechanism; In the second state, the releasable connector disengages from the control line, and the vehicle is able to tilt laterally independently of the actuator.

20. The vehicle according to claim 19, wherein, The controller is configured to operate the actuator and the tilt control mechanism in the first state and the first mode, such that it tends to keep the vehicle upright regardless of changes in terrain.

21. The vehicle according to claim 20, wherein, The controller is configured to achieve closed-loop control of vehicle tilt based on the sensed deviation between the vehicle's lateral tilt and vertical tilt.

22. The vehicle according to any one of claims 19 to 21, wherein, The controller is configured to operate in a second mode in which it adjusts the lateral tilt of the vehicle to compensate for changes in terrain and also tilts the vehicle in the steering direction.

23. The vehicle according to any one of claims 19 to 21, further comprising a leveling control mechanism, said leveling control mechanism: Operable in a first direction, such that both the left and right wheels move upward relative to the chassis; and It can be operated in a second direction so that both the left wheel and the right wheel move downward relative to the chassis.

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