WO2019020645A1

WO2019020645A1 - Self-balancing, single-axle running-gear unit having a stair-climbing function

Info

Publication number: WO2019020645A1
Application number: PCT/EP2018/070067
Authority: WO
Inventors: Christoph Sauer; Andreas Scheuerer; Christian Friedrich; Felix WEIHRAUCH; Simon SANKTJOHANSER; Thomas Luft
Original assignee: Christoph Sauer
Priority date: 2017-07-25
Filing date: 2018-07-24
Publication date: 2019-01-31
Also published as: EP3658096B1; EP3658096A1

Abstract

The invention relates to a self-balancing, single-axle running-gear unit (10), comprising: a movement module (12) having a drive axle (14) on which two drive wheels (16, 18) are rotatably mounted, and a drive (28) which can be coupled to the two drive wheels; a stair-climbing module (46) having two spoked stars (54) which are mounted so as to be rotatable about the drive axle (14), wherein each spoked star (54) has a plurality of radially extending supporting spokes (56) which are arranged with an offset in the circumferential direction and which have a radially outer, free end on which a ground contact element is fitted, and wherein each spoked star (54) is arranged laterally next to one of the drive wheels (16, 18); and a controller which contains an inclination sensor and/or an acceleration sensor and is configured, by controlled application of a torque to the drive wheels (16, 18) and/or to the spoked stars (54), to prevent or to limit tilting of the load-receiving interface (42) relative to a vertical (V) extending through the load-receiving interface (42) in an initial state.

Description

Self-balancing, single-axle chassis with stair climbing function

The invention relates to a self-balancing, single-axle chassis with a stair climbing function. By 'stair climbing function' it is meant in particular that the chassis is capable of moving up and down stairs either by itself or by the power of a user, but the stair climbing function can also be used to bridge other obstacles such as curbs, To overcome thresholds or the like.

Transport tasks are manifold today. For example, sometimes heavy goods must be loaded in transport vehicles and unloaded again at the destination. In homes without an elevator, heavy items must often be transported through the stairwell over several floors. In an industrial environment (such as in a factory or in logistics), loads of all kinds have to be moved back and forth, often in confined spaces.

In particular, when transporting physically disabled, sick or injured people, the increasing number of persons with increased body weight complicates the transportation task to be solved. In addition, there are often spatial restrictions such as narrow staircases, narrow corridors and the like. Paramedics and people working in hospitals or nursing homes, therefore, are increasingly exposed to greater burden in the rearrangement and transport of patients. It should also be taken into account that under certain circumstances a patient transport may also have to take place under adverse conditions (weather, falling or rising surfaces, uneven or slippery surfaces, etc.), which may make it even more difficult.

There is therefore basically the desire for a compact and well maneuverable transport device, which simplifies a solution of the described and other transport tasks.

This object is achieved by a self-balancing, single-axle chassis with the features specified in claim 1. Accordingly, the chassis according to the invention includes a movement module with a drive axle on which two drive wheels are rotatably mounted. A preferably electrical shear and also belonging to the chassis drive can be coupled with the two drive wheels. The chassis according to the invention further comprises a load-bearing module having a first arm extending from the movement module and a second arm. The second arm has a first end hingedly connected to the first arm and a second end to which a load receiving interface is preferably hinged. The load-receiving interface serves to connect to the object to be transported or to a transport device in or on which objects or goods to be transported are located. For example, the load-receiving interface can be designed for releasably securing a stretcher. Alternatively, the load-receiving interface can be used to connect to a basket or other container containing goods to be transported. The load receiving interface may also be configured to support a support platform on which objects to be transported are deposited. The load-receiving interface can be a standardized load-receiving interface. In particular, the load-receiving interface can be designed to allow quick attachment and detachment of a transport device to be connected with it. By varying the angle between the first arm and the second arm of the load-carrying module, the load-bearing interface can be brought into a higher or lower position.

The chassis according to the invention is further equipped with a stair climbing module having two spoke stars which are mounted so that they can rotate about the drive axle. In other words, the two drive wheels and the two spoke stars of the chassis according to the invention can rotate about the same axis. In each case a spoke star is arranged laterally next to one of the drive wheels. With respect to the drive axle, the spoke star associated with a drive wheel can be arranged laterally outside the drive wheel, but in a preferred embodiment of the chassis according to the invention it is arranged laterally within the assigned drive wheel.

The term "spoke star" here means a one-part or multi-part component with a center which is arranged coaxially to the drive axis and from which a plurality of support arms, referred to as support spokes, at least in the manner of a spoke

Extend substantially radially outward. At the radially outer, free end of each support spoke a ground contact element is mounted, with which the support spoke can be supported on the ground on which the chassis is located. The ground contact element may for example be a foot, preferably made of a non-slip material, such as rubber or a rubbery elastomeric material. The foot may be attached to the free end of the support spoke or may surround the free end of the support spoke. For example, each foot may be a molded part, which is pushed onto the free end of the associated support spoke. Each foot, by its shape, can enable or support rolling on the ground. For this it is not necessary that the foot is rotatably mounted on the support spoke. In a preferred embodiment of the chassis according to the invention, at least some of the ground contact elements are wheels which are rotatably mounted on or in the vicinity of the free end of the associated support spoke.

Finally, the chassis according to the invention has a controller that includes a tilt sensor and / or an acceleration sensor and is configured to prevent or control tilting of the load receiving interface with respect to a vertical line passing through the load receiving interface by controlled application of torque to the drive wheels and / or spoke stars limit. It should be noted in this connection that the vertical running through the load-bearing interface always means that vertical which, in an initial state, passes through the load-bearing interface, ie before the load-receiving interface tilts. Depending on the ground on which the chassis is located, the torques applied to the drive wheels and / or spoke stars may be the same or different for both drive wheels or spoke stars. Depending on the situation, a torque can also be applied to just one drive wheel or a spoke star. With the tilting of the load receiving interface with respect to a running through the load receiving interface vertical is meant primarily a tilting about the drive axle, ie, a tilting forward or backward. However, alternatively or additionally, also a lateral tilting of the load receiving interface may be meant, ie tilting to the left or right which may also be prevented by the control, for example by first driving the chassis by driving only one of the two drive wheels or by driving the two drive wheels in opposite directions is rotated about its vertical axis (z-direction, see also Fig. 2) that can be counteracted by subsequent controlled application of torque to the drive wheels (or spoke stars) tilting of the load receiving interface. The self-balancing or self-stabilizing function described above is already known from the prior art, for example from DE 10 2011 084 236 A1 or DE 600 21 419 T2. It may therefore be omitted in the following to describe in detail the required control and its operation.

Basically, the ability to self-balance is based on an inverse pendulum control, that is, a pendulum whose weight is at the top and whose pivot point is below the weight. At equilibrium, the weight and pivot point are on a vertical which passes through the center of gravity and center of gravity of the weight. When the weight leaves its equilibrium state on the vertical (this corresponds to the tilting of the load-bearing interface in the present invention), the controller tries to counteract this. A control strategy is to restore equilibrium. This goal can be achieved by returning the weight to its original position by a controlled force or torque action. However, this goal can also be achieved by bringing the pivot point of the system to a new position below the weight, more specifically to a position located on a vertical which extends in the current position of the weight through the center of gravity of the weight. In the case of a more complex system, the term "center of gravity" always means the resulting center of gravity of the overall system, in the case of the present invention, for example, the resulting center of gravity of the chassis or, if the chassis is used to solve a haulage task, the resulting center of gravity of the chassis the load transported with him.

However, at least for the purposes of the present invention, it is not a necessary condition to position the resulting center of gravity of the overall system vertically above the pivot point of the system. Rather, the control of the chassis of the invention may allow for imbalance conditions of the overall system as long as the force of the chassis drive is sufficient to apply a torque compensating for the imbalance to the drive wheels and / or the spoke stars so as to prevent the chassis from tipping over. It is understood that in such a case that for the compensation of a currently existing

Unbalance state necessary torque permanently and not only momentarily must be applied to the drive wheels and / or spoke stars. It is therefore also understood that in the context of the present invention in relation taken initial state from which a tilting of the load receiving interface takes place, a state of equilibrium of the overall system or an unbalance state of the entire system can be. The vertical in the initial state through the load receiving interface vertical therefore does not necessarily have to run through the pivot point of the entire system in the initial state.

In preferred embodiments of the chassis according to the invention, the control is operable in at least two operating modes, a so-called standstill mode and a movement mode. The standstill mode serves to automatically stabilize the chassis at standstill, i. to prevent overturning of the chassis. In Stiilstandsmodus therefore preferably a tilting of the load receiving interface with respect to the running in the initial state through the load receiving interface vertical is not allowed or only as far as it is necessary to detect an incipient tilting. Moving the chassis is not supported in standstill mode. However, in a standstill mode, the undercarriage may perform those movements necessary to prevent tilting of the load receiving interface with respect to the verticals through the load receiving interface, such as rotating the chassis around its vertical axis by unidirectionally driving a drive wheel or driving both drive wheels (and / or spoke stars in opposite directions) ).

In the motion mode, the controller is preferably configured to merely limit tilting of the load-receiving interface with respect to the vertical in the initial state through the load-receiving interface. In other words, a degree of tilting of the load-bearing interface with respect to the vertical, in particular forward and backward, may be permitted and in particular serves to detect a user's desire for the chassis to move forward or backward. Upon detecting such a user request, the controller limits tilting of the load receiving interface with respect to the vertical extending therethrough, preferably by rotating the drive wheels in the tilt direction. As a result, on the one hand counteracts further tilting of the load receiving interface and on the other hand, the chassis moves automatically in the direction desired by the user. During the movement of the chassis, the tilt angle can be returned to zero, ie the load receiving interface is then again on the before the start of tilting through them Verti cal. In the movement mode, the controlled application of a torque to the drive wheels (and / or spoke stars) can take place in such a way that the chassis automatically moves in the desired direction after detecting a corresponding user request. In this case, the speed of locomotion can be specified. The user then needs to exert no additional force for this movement of the chassis. The controlled application of torque to the drive wheels can also take place in the movement mode so that the drive of the chassis is only supportive, ie the user still has to apply a certain force, which is preferably adjustable, for the movement of the chassis.

In preferred embodiments of the chassis according to the invention, the controller is additionally configured to counteract tilting of the load receiving interface with respect to a vertical line passing through it by dynamically varying an angle between the first arm and the second arm of the load-carrying module. By adjusting the angle between the first arm and the second arm of the load-carrying module resulting for the entire assembly (chassis plus possibly attached to the load receiving interface load) resulting, the center of gravity can be brought into a position in which a tilting of the load receiving interface with respect to they are minimized or prevented from running vertical. By dynamically changing the position of the resulting center of gravity, the torques required to be applied to the drive wheels (and / or spoke stars) to prevent or limit the tipping of the load receiving interface can be minimized. An overload of the drive can be better prevented in this way.

The stair climbing module of a chassis according to the invention is designed such that when coming into contact with a staircase or a similar obstacle at least a part of the ground contact elements of each spoke star gets into engagement with the steps. This can be achieved, for example, by allowing the drive wheels of the chassis to compress to the extent of contact with the edge of a step so that at least one ground contact element of each spoke star of the stair climbing module comes into load-bearing contact with the step, such that the chassis is locked to the spoke stars mounted floor contact elements on the stairs can "roll". In one embodiment, the drive wheels of the chassis are pneumatic and are in communication with a tire pressure control system that allows air to flow To supply drive wheels and to discharge from them. In such an embodiment, when the chassis is to ascend or descend a flight of stairs, air may be released from the drive wheels until ground contact elements of the spoke stars of the stair climbing module come into load-bearing contact with a stair step. After overcoming the staircase, the tire pressure control system can again introduce air into the drive wheels to make it functional. The tire pressure control system may for this purpose have a mounted on the chassis compressed air reservoir, from which the air is supplied to the drive wheels. The aforementioned tire pressure control system can thus enable the function of the stair climbing module, but it can also be provided only to always provide for a correct pressure pneumatic wheels drive.

The stair climbing module may be configured to easily rotate in one direction and to resist in the opposite direction of rotation. In this way, such a chassis can be pulled up a flight of stairs by a user without the stair climbing module resisting this movement, whereas that

Chassis is slowed down when shutting down a staircase through the then-acting rotational resistance, whereby the user-applied holding force is reduced.

In preferred embodiments of the chassis according to the invention, each spoke star can be coupled to the drive of the chassis. In this way, an automatic or at least power-assisted driving up and down of the chassis via a staircase or overcoming an obstacle can be realized. Preferably, when the spoke stars are coupled to the drive, the controller is configured to prevent or prevent tilting of the load receiving interface with respect to a vertical line through the load receiving interface by controlled application of torque to the spoke stars or only to the spoke stars instead of the drive wheels limit. Since the spoke stars are then coupled to the drive, if any part of their ground contact elements is in load-bearing connection with a step, and since the spoke stars with their ground contact elements then often take over the majority of the load transfer from the chassis to the ground, the controlled application of a Torque to the spoke stars to avoid tipping the load receiving interface more effective than applying a torque to the drive wheels. If necessary, the controlled bring a torque but done both on the spoke stars and on the drive wheels when the drive wheels are still in contact with the ground. A corresponding sensor similar to a wheel slip control in motor vehicles, the required to avoid tilting of the load receiving interface torque in cooperation with the controller suitable between the

Split spoke stars and drive wheels.

Constructively, each spoke star can be designed so that it includes a number of its ground contact elements corresponding number radially extending to the drive axle support spokes whose radially inner end is rotatably mounted on the drive axle, wherein at the radially outer end of the support spokes each of the ground contact element is mounted. In the circumferential direction, the angular offset of the support spokes of a spoke star is preferably constant, i. in a spokes star with three support spokes, the support spokes and thus the ground contact elements are arranged at an angular distance of 120 °.

The support spokes of a spoke star may have a length which is smaller than the radius of the associated drive wheel. The ground contact elements mounted on a spoke star are then not in load-bearing contact with the ground on which the chassis is located during normal operation of the chassis, i.e., when no steps have to be negotiated. However, in the manner already described above, they can come into load-bearing contact with a stair step if the function of the stair step module is to be used.

Alternatively, the support spokes of each spoke star can be made adjustable in length, wherein its shortest length is smaller than the radius of the associated drive wheel, and wherein its largest length is greater than the radius of the associated drive wheel. The length adjustability of the support spokes can for example be realized in a hydraulic manner by a part of each support spoke is hydraulically moved relative to another part of the support spoke. The length adjustment can also be realized electromechanically, for example by means of a driven by an electric motor spindle / nut assembly. In the retracted position (shortest length of the support spokes), the ground contact elements of each spoke star are not in load-bearing contact with the spokes

Underground on which the chassis is located, and thus do not hinder unwinding of the drive wheels. In the extended position of the support spokes (largest Length of the support spokes) protrude at the radially outer end of the support spokes mounted ground contact elements radially beyond the associated drive wheel, so that a stair climbing function can be realized in which the drive wheels of the chassis are in no or at best supporting contact with the ground. This allows the execution of the stair climbing function.

Also in embodiments of the chassis, in which the support spokes are adjustable in length, the support spokes may be part of a spokes star, which is rotatably mounted on the drive axle and, if desired, can be coupled to the drive of the chassis. Regardless of whether the support spokes are adjustable in length or not, the term "support spoke" should not limit the corresponding element to a narrow, elongated body, but the underlying function is crucial. A support spoke in the context of the present invention may for example also be a planar body, which establishes the connection between the ground contact element and the drive axle. Such a flat body can also taper from its base adjacent the drive axle to its free end.

As already mentioned, in a preferred embodiment, the ground contact elements are designed as rotatable wheels. The wheels attached to a spoke star thereby form a wheel group, wherein each wheel of a wheel group is arranged at a radial distance from the drive axle and is rotatably mounted.

In certain embodiments of the chassis according to the invention, the first arm of the load-carrying module is rigidly connected to a housing of the chassis. In the housing of the chassis, the drive of the chassis can be arranged. Overall, this results in a simplified structural design of the chassis. The drive of the chassis can be designed so that it can also adjust the angle between the first arm and the second arm of the load-carrying module. Alternatively, preferably in the joint between the first arm and the second arm of the load-carrying module, a separate drive for adjusting the angle between the first arm and the second arm may be present, which can cooperate with the controller.

In all embodiments of a chassis according to the invention, emergency wheels can be rotatably mounted on a hinge axle, on which the first arm and the second arm of the load-bearing module are connected to one another in an articulated manner. These emergency wheels serve to provide a further support point for the chassis when, for some reason, the controller can not prevent tipping over of the chassis or when the drive of the chassis fails, for example, in a power failure, so that the self-stabilizing function of the chassis according to the invention is no longer given is. In such an emergency, an undercarriage according to the invention can then roll on its drive wheels and the emergency wheels which are likewise supported on the ground in this emergency state.

The drive of the chassis according to the invention may, as already mentioned, be located in a housing of the chassis. Such a housing is preferably arranged around the drive axis. Alternatively and / or additionally, however, the drive can also be located in the drive wheels themselves. For example, each drive wheel may have a wheel hub motor. As already mentioned, the drive is preferably an electric drive, e.g. in the form of one or more electric motors. If necessary, the drive is also assigned a differential. The drive may have a transmission for over or under the driving force of the (electric) motor. The gearbox can be a Harmony Drive gearbox that integrates well with the drive axle, along with one or more electric motors. Such coupled with an electric motor Harmony Drive transmission is also suitable as another drive for adjusting the angle between the first arm and the second arm of the support module.

To power the drive and the controller is preferably a power storage in the form of a rechargeable battery, which is attached to a suitable location of the chassis. Lithium batteries are currently preferred because of their high current density and low weight.

Chassis according to the invention are preferably provided with a user interface, for example in the form of an operating panel, which may be designed as a touchscreen. Through this user interface, the various operating modes can be selected and important operating parameters entered.

Overall, a compact and extremely versatile device is realized with the chassis according to the invention, which leads in many areas to a significant facilitation of a transport task to be solved and helps to avoid physical overload or damage to a user. Presently preferred embodiments of a chassis according to the invention are explained in more detail below with reference to the accompanying schematic drawings. It shows:

1 is a first embodiment of a chassis according to the invention seen in a spatial representation obliquely from above,

2 shows the chassis of FIG. 1 in a side view,

3 is a front view of the chassis of FIG. 1,

4 is a plan view of the chassis of FIG. 1,

5 shows a chassis according to the figures 1 to 4 when overcoming a staircase, wherein a facing the viewer drive wheel of the chassis is not shown in order to better recognize the function of a stair climbing module,

6a shows an alternative embodiment of a stair climbing module of a chassis according to the invention, wherein wheels of the stair climbing module are in a position in which a stair climbing function is enabled,

Fig. 6b, the alternative embodiment of the stair climbing module of Fig. 6a in a state in which the wheels of the stair climbing module are in a position in which a normal movement of the chassis is possible, and

Fig. 7 shows a slightly modified embodiment of the chassis of FIG. 1 with a stretcher mounted on it.

FIGS. 1 to 4 show a first exemplary embodiment of a self-balancing, uniaxial chassis 10 in various views. The chassis 10 has a so-called movement module 12, which has a drive axle 14 on which two drive wheels 16 and 18 are rotatably mounted at a distance from each other. In the illustrated embodiment, the two drive wheels 16, 18 pneumatic wheels, which are rotatably mounted at the two ends of the drive axle 14. each Drive wheel 16, 18 thus includes a pneumatic tire 20, 22 mounted on a wheel rim 24, 26.

The movement module 12 further includes a drive 28 which can be coupled to the two drive wheels 16, 18 and which is received in the housing 30 in the exemplary embodiment shown, through which the drive axle 14 extends or into which the drive axle 14 protrudes from both sides. The drive shaft 14 may therefore consist of several coaxially arranged parts. The drive 28 here consists of two ^accommodated in the housing 30, not shown electric motor ren, of which one with the drive wheel 16 and the other with the drive wheel 18 can be coupled. Each electric motor can be interlocked with a gear ^¬ example, a harmonic drive gear, which is well-suited for placement in the near ^¬ approximately tubular housing 30th The gearbox serves

In particular, to increase the output torque provided by the electric motor by a suitable reduction accordingly, in order to apply a high torque to the Antriebsrä ^¬ of 16 and 18, even when using a relatively small electric motor can.

The chassis 10 further includes a load support module, generally designated 32, which has a first arm 34 extending from the movement module 12. In the embodiment shown, the first arm 34 is integral with the housing 30 of the movement module 12 or otherwise rigidly connected to the housing 30, for example screwed. The load bearing module 32 further includes a second arm 36 having a first end 38 hingedly connected to the first arm 34 and a second end 40 to which a load receiving interface 42 is hinged. An angle β between the first arm 34 and the second arm 36 may be adjusted to raise or lower the load receiving interface 42. In order to adjust the angle β, an output driven by the drive 28 through the first arm 34 can serve, for example in the form of a worm shaft drive. Alternatively, in the existing between the first arm 34 and the second arm 36, a separate drive motor may be arranged, with which the relative position of the two arms 34 and 36 and thus the angle ß can be changed.

The load-receiving interface 42 shown here only schematically serves to produce a releasable connection with a load to be transported by means of the chassis 10. FIG. 7 shows a stretcher 44 at the load-receiving interface 42 attached. Instead of the stretcher 44 may be attached to the load receiving interface 42 but for example, a basket or other container, which serves to accommodate objects to be transported. It is also possible to attach to the load-receiving interface 42 only a support plate (not shown), can be sold on the transported objects. The load-receiving interface 42 is preferably designed as a quick-fastening interface, in order to enable simple and time-saving attachment and detachment

allow transporting load or a serving container.

The chassis 10 is further provided with a so-called stair climbing module 46, which has two wheel groups 48, 50, in which three circumferentially equally spaced wheels 52 are in the embodiment shown. Each wheel group 48, 50 is assigned to one of the drive wheels 16, 18 and, in the exemplary embodiment shown, is arranged laterally next to the associated drive wheel 16 or 18 such that it is rotatable about the drive axle 14. More specifically, each wheel group 48, 50 comprises a spokes star 54, each with three support spokes 56, at the radially outer end of each wheel 52 is rotatably mounted. The radially inner ends of the support spokes 56 form the center of the spoke star 54, which is rotatably mounted on the drive axle 14. In the illustrated embodiment, the spoke star 54 is made in one piece, but it can also be multi-part.

Each wheel group 48, 50 is arranged axially offset in the illustrated embodiment with respect to the associated drive wheel 16 or 18. Each wheel 52 has a significantly smaller diameter than the drive wheels 16 and 18. Also, a circle virtually enveloping the outside of the three wheels 52 of a wheel group has a smaller diameter than the drive wheels 16 and 18, so that in normal operation, i. without the use of a stair climbing function, only the drive wheels 16 and 18 are in contact with the ground on which the chassis 10 is located.

In the illustrated embodiment, each wheel 48, 50 with the drive 28 koppeibar so that the chassis 10 can automatically perform a later described in more detail stair climbing function. More specifically, the two on the drive shaft 14 rotatably mounted spoke stars 54, if necessary, can be coupled to the electric motor, which is responsible for a drive of the respective wheel group 48 or 50 associated drive wheel 16 or 18. Finally, the chassis 10 has a controller with a user interface, not shown. The user interface may be, for example, a control panel, such as a touchscreen, which may be attached to the first arm 34 or the second arm 36. This user interface allows, for example, the selection of different operating modes and input and control of various operating parameters. However, the user interface need not be attached to the chassis 10, but may also communicate wirelessly with the control of the chassis 10. For example, the user interface may be implemented as an app that can be loaded onto a smartphone to allow a user of the chassis 10 to control the chassis 10 via his smartphone.

The control of the chassis 10 includes a tilt sensor (not shown) and an acceleration sensor (not shown) mounted at appropriate locations on the chassis 10. The controller is configured to limit by controlled application of a torque to the drive wheels 16, 18, tilting of the load receiving interface 42 relative to verhin an axis extending in an initial state by the load-receiving interface 42 vertical V ^¬ countries or in any case by means of the drive 28th The initial state is that state that is present before tilting the load-receiving interface 42. The initial state is in any case a stable state, but does not need to be an equilibrium state, but may be an artificially stabilized state by applying a compensating torque to the drive wheels 16, 18 and / or the wheel assemblies 48, 50. In other words, the task of the controller is to stabilize the due to the uniaxial design of the chassis 10 latent unstable state and in particular to prevent the vehicle frame 10 tipping forward or backward, if desired, but also to the left or right, both at a stoppage of the chassis 10 as well as when the chassis 10 is in a locomotion.

In a selectable via the user interface standstill mode, the chassis 10 automatically performs no serving for its movement movement. Rather, the controller in this standstill mode only has the task of balancing the chassis 10 including an optionally attached to the load receiving interface 42 load or to stabilize, ie to prevent it from tipping over. To this end, based on the data provided by the inclination sensor and the acceleration sensor, the controller applies, if that data, a tilting of the load-receiving interface 42 relative to that through the load-receiving interface 42 extending vertical view, a tilt compensating torque on the drive wheels 16 and / or 18 on. In a stair climbing mode described in more detail later, the torque compensating a tilting can be additionally or even exclusively applied to the wheel groups 48, 50.

The amount of tilting can be expressed by a tilt angle cp that is set in a tilted state between the vertical V passing through the load receiving interface 42 and the position of the load receiving interface 42. In the untilted state, this tilt angle cp is zero, since the load receiving interface 42 is in the untilted state on the vertical V. In a tilting operation forward or backward, the chassis 10 rotates about a rotational axis D, which results from a compound of the two ground-contacting support points of the drive wheels 16 and 18 of the chassis 10 (see Fig. 2). The in the initial state through the load receiving interface 42 extending vertical V can intersect the axis of rotation D when the load receiving interface 42 in the initial state is exactly vertical over the axis of rotation D. As a rule, this vertical V will not intersect the axis of rotation D.

The control of the chassis 10 endeavors, after detecting an incipient tilting of the chassis 10, to bring the tilt angle φ back to zero by applying a counter torque corresponding to the tilting moment to the drive wheels 16, 18 and / or the wheel assemblies 48, 50. To return the tilt angle cp to zero, it may be necessary that the applied counter torque is at least temporarily greater than the overturning moment. In principle, by applying the counter-torque to the drive wheels 16, 18 and / or the wheel assemblies 48, 50, a state of the chassis 10 tilted with respect to the initial condition can be stabilized and then used as a new starting condition.

In the stabilized state of the chassis 10, only the counter torque corresponding to the currently acting tilting moment needs to be applied to the drive wheels 16, 18 and / or the wheel assemblies 48, 50. By adjusting the angle β between the first arm 34 and the second arm 36, it can be ensured that a tilting moment acting in the stabilized state is minimized or even eliminated. The smaller the tilting moment acting in the stabilized state, the smaller the counter-torque securing the stabilized state can be, which must be applied to the drive wheels 16, 18 and / or the wheel assemblies 48, 50. A control strategy of the chassis 10 can therefore are to minimize by appropriately adjusting the angle ß a remaining tilting moment, in order to reduce the power consumption of the drive 28 and counteract an overload of the drive 28 in this way. Furthermore, by dynamically adjusting the angle β during operation of the chassis 10, it is possible to prevent a condition occurring in which the drive 28 is no longer capable due to its inherently limited power of a sufficiently large counter torque for tilting torque compensation corresponding to a tilting moment applied.

The chassis 10 may be configured to not support locomotion, i. that a user must push the chassis 10 and any load on it with his own force to bring an object to be transported to another location. The above-described self-stabilizing function of the chassis 10 is maintained even during such shifting of the chassis 10.

Advantageously, however, the drive 28 of the chassis 10 can be used to assist locomotion of the chassis or even to enable it automatically. For this purpose, a movement mode can be selected via the user interface, in which the control of the chassis 10 recognizes the desire of a user to move the chassis, and then supports this movement or even executes it automatically. In order to recognize such a user request, for example, a slight tilting of the load receiving interface 42 relative to its initial state may occur in the movement mode, for example when a user starts pushing the chassis 10 on a handle (not shown) in the desired direction. The control of the chassis 10 may then, in addition to the counter torque required for stabilization, apply a torque to the drive wheels 16, 18 and / or the wheel assemblies 48, 50, which assist or independently drive the travel of the chassis 10 in the desired direction. For example, a maximum speed with which the chassis 10 is to travel can be specified via the user interface. Even in the movement mode takes place at any time a self-balancing or self-stabilization of the chassis 10 to prevent tipping over of the chassis 10.

In FIGS. 1 to 4, an upper side 58 of the load-receiving interface 42 is always shown in a horizontal position. However, this top 58 may depend on which load is connected to the load receiving interface 42, also located in a position deviating from the horizontal. For example, if the load-receiving interface 42 is connected to a seat (not shown) for transporting a person, then it is usually more comfortable and safer if that seat is in a somewhat reclined position. A stabilized state of the chassis 10 therefore does not require a horizontal position of the load receiving interface 42 and in particular its top 58th

Depending on the transport task to be solved, however, it may be desirable to always keep the load receiving interface 42 and in particular its upper side 58 in a horizontal position in order to minimize additional tilting moments acting on the chassis 10 and / or to prevent objects to be transported from being transported fall out of the transport container connected to the load receiving interface 42 or flow out. The chassis 10 may therefore at the articulated connection between the second end 40 of the second arm 36 and the load receiving interface 42 an auxiliary drive (not shown), for example in the form of another electric motor with or without gear, which cooperates with the control of the chassis 10 and based on the supplied sensor data dynamically ensures that the load receiving interface 42 is always in a horizontal position.

The chassis 10 may also be operated in a stair climbing mode, which may be a sub-mode of the movement mode. This stair climbing mode will now be explained in more detail with reference to Figures 5 and 6.

In stair climbing mode, the wheels 52 of the wheel assemblies 48 and 50 are the predominantly or even exclusively load bearing wheels of the chassis 10. Contacting the wheels 52 with a step or other obstacle to be overcome may be in the first embodiment shown in Figs of the chassis 10 are made possible by the fact that the pneumatic tires 20, 22 of the drive wheels 16, 18 are designed so that they can compress when contacted with an edge of a step so far that one or more wheels 52 of a wheel group 48, 50 in load-bearing Contact the stairs. For example, the pneumatic tires 20, 22 may be so-called balloon tires that require only low air pressure and therefore can be compressed sufficiently easily. Alternatively, the pneumatic tires 20, 22 may communicate with a tire pressure control system that allows air to escape from the Release tires 20, 22 and re-supply after overcoming a staircase or other obstacle.

FIG. 5 shows schematically how the wheels 52 of a wheel group 48, 50 are in contact with steps. By driving the associated spoke star 54, on which the wheels 52 are rotatably mounted, the chassis 10 can move up the stairs or at least support the upward movement. Likewise, when the chassis 10 is to descend a flight of stairs, a suitable counter-torque may be introduced from the drive 28 into the spoke stars 54, which decelerates the downward movement of the chassis 10 and thereby relieves a user of the chassis 10 holding the chassis. The control of the chassis 10 may also be adapted to allow a fully automatic up and down travel of the chassis 10 via a staircase. After the staircase (or other obstacle) has been overcome, further movement of the chassis 10 takes place again by means of the drive wheels 16, 18, as already described above.

FIGS. 6a and 6b schematically show an alternative embodiment of the stair climbing module 46. In contrast to the exemplary embodiment described above, the support spokes 56 are designed to be adjustable in length and can be adjusted from a retracted position shown in FIG. 6b to an extended position shown in FIG. 6a and back. In this case, the state shown in FIG. 6a corresponds to the stair climbing mode in which step-shaped or other obstacles can be overcome by driving the spoke stars 54, because the wheels 52 located on the support spokes 56 have moved into a position due to the extension of the support spokes 56 they are beyond the outer periphery of the drive wheels 16, 18 and thus can come into contact with, for example, a staircase. The state shown in Figure 6b corresponds to the normal standstill or movement mode without stair climbing function. In this state, the wheels 52 are displaced by the retraction of the support spokes 56 into a position within the outer periphery of the drive wheels 16, 18.

Finally, a chassis 10 is shown in Figure 7 similar to the embodiment shown in Figures 1 to 5, on the load receiving interface 42 a stretcher 44 is attached. The stretcher 44 is provided at both ends with a handle 60 to a user (doctor, nurse, nursing staff) a simple back and forth of the chassis 10 with it mon- allowed stretcher 44. In such a case, the chassis 10 itself need not have a handle. Indicated at 62 is a compressed air reservoir which is fixed to the first arm 34 of the chassis 10 and belongs to the tire pressure control system. If air has been released from the tires 20, 22 to enable the stair climbing function, after overcoming the stairs, air may be supplied to the tires 20, 22 from the compressed air reservoir 62 again to restore proper functioning of the drive wheels 16, 18. Alternatively, it is also conceivable to manufacture the tires 20, 22 from a material which has sufficient stability during normal operation and yet allows the stair climbing mode to allow the tires 20, 22 to compress far enough to permit load-bearing engagement of the wheels 52 allow the stair climbing module 46.

In the illustrated embodiments of the chassis 10, emergency wheels 64 are rotatably mounted on a hinge axis to which the first arm 34 and the second arm 36 of the load-bearing module 32 are hinged together. These emergency wheels 64 serve to provide a further support point for the chassis 10 when, for some reason, the control can no longer prevent the chassis 10 from tipping over, for example when the drive 28 of the chassis 10 fails, such as in the event of a power failure the self-stabilizing function of the chassis 10 is no longer given. In such an emergency, the chassis 10 can roll on its drive wheels 16, 18 and in this emergency state also supported on the ground emergency wheels 64.

Claims

claims

1. Self-balancing, single-axle chassis (10), with

- A movement module (12) having a drive axle (14) on which two drive wheels (16, 18) are rotatably mounted, and one coupled to the two drive wheels drive (28),

- A load-bearing module (32) having a first arm (34) extending from the movement module (12) and a second arm (36) having a first end (38) pivotally connected to the first arm (34) , and a second end (40) to which a load receiving interface (42) is attached,

a stair climbing module (46) having two spoke stars (54) rotatably mounted about the drive axle (14), each spoke star (54) having a plurality of circumferentially offset and radially extending support spokes (56) having a radially outer, free one End has, at which a ground contact element is attached, and wherein in each case a spoke star (54) is arranged laterally next to one of the drive wheels (16, 18), and

a controller including a tilt sensor and / or an acceleration sensor and configured to tilt the load receiving interface (42) with respect to one in a by applying a torque to the drive wheels (16, 18) and / or the spoke stars (54) Initial state by the load-receiving interface (42) extending vertical (V) to prevent or limit.

2. Chassis according to claim 1,

characterized in that the controller is configured to prevent tilting of the load receiving interface (42) with respect to the vertical (V) passing through the load receiving interface (42) in a stall mode.

3. Chassis according to claim 1 or 2,

characterized in that the controller is configured to limit, in a motion mode, tilting of the load-receiving interface (42) with respect to the vertical (V) passing through the load-receiving interface (42).

4. Chassis according to claim 3,

characterized in that the controller is configured to operate in motion Mode to limit tilting of the load receiving interface (42) with respect to the through the load receiving interface (42) extending vertical (V) by rotating the drive wheels (16, 18) in the tilting direction.

5. Chassis according to one of the preceding claims,

characterized in that the support spokes (56) of each spoke star (54) have a length which is smaller than the radius of the associated drive wheel (16, 18).

6. Chassis according to one of claims 1 to 4,

characterized in that the support spokes (56) of each spoke star (54) are adjustable in length, with a shortest length which is smaller than the radius of the associated drive wheel (16, 18), and a maximum length greater than the radius of the associated one Drive wheel (16, 18).

7. Chassis according to one of the preceding claims,

characterized in that each spoke star (54) is coupleable to the drive (28), wherein when the spoke stars (54) are coupled to the drive (28), the controller is configured to also apply torque by applying a torque Spokes stars or exclusively on the spoke stars instead of the drive wheels (16, 18) to prevent tilting of the load-receiving interface (42) with respect to a through the load-receiving interface (42) extending vertical (V) or limit.

8. Chassis according to one of the preceding claims,

characterized in that each spoke star (54) with respect to the drive axle (14) laterally within the associated drive wheel (16, 18) is arranged.

9. Chassis according to one of the preceding claims,

characterized in that each ground contact element is a wheel (52) rotatably mounted at the free end of the associated support spoke (56).

10. Chassis according to claim 9,

characterized in that the stair climbing module (46) has spoke stars (54) with at least three support spokes (56), wherein the wheels (52) of each spoke star (54) each form a wheel group (48, 50).

11. Chassis according to one of the preceding claims,

characterized in that the drive wheels (16, 18) are pneumatic and are in communication with a tire pressure control system adapted to supply air to and out of the drive wheels (16, 18).

12. Chassis according to claim 11,

characterized in that the tire pressure control system has an attached to the chassis compressed air reservoir (62).

13. Chassis according to one of the preceding claims,

characterized in that the controller is additionally configured to dynamically alter an angle (β) between the first arm (34) and the second arm (36) of the load bearing module (32) to tilt the load receiving interface (42) counteract a through the load-receiving interface (42) extending vertical (V).

14. Chassis according to one of the preceding claims,

characterized in that the first arm (34) of the load-bearing module (32) is rigidly connected to a housing (30) of the chassis.

15. Chassis according to one of the preceding claims,

characterized in that at a hinge axis, on which the first arm (34) and the second arm (36) of the load-bearing module (32) are hinged together, emergency wheels (64) are mounted.

16. Chassis according to one of the preceding claims,

characterized in that the load-receiving interface (42) for attachment of a stretcher (44) is executed.