A TROLLEY

FIELD OF THE INVENTION

The present invention relates to a trolley, a method of providing power to a trolley and to a computer program element and a computer readable medium.

BACKGROUND OF THE INVENTION

Pushing strollers, or prams/buggies, trolleys, supermarket or hardware store trolleys can be physically exhausting, especially on non-paved paths, uneven terrain and with a heavy load such as a child and/or other items or equipment. DE 102013216679A1 proposes, in a similar way to that used for E-Bikes, to provide assistance by electric motors. Additionally, two simple buttons or dials can be provided on the handle in order to enable a user to interact with the stroller or trolley - https://www.foppapedretti.it/en/child- technology/travel-systems/myo-tronic-platinum-electric-strol ler.

However, there is need to improve such strollers/trolleys.

SUMMARY OF THE INVENTION

Therefore, it would be advantageous to have an improved trolley and method of providing power to a trolley.

The object of the present invention is solved with the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the following described aspects of the invention apply also for the trolley and for the method of providing power to a trolley, as well as for the computer program element and computer readable medium.

In a first aspect, there is provided a trolley, comprising:

a frame;

a plurality of wheels;

at least one motor; a handle;

a plurality of sensor elements; and

a processing unit.

The plurality of wheels are rotational connected to the frame and configured to support the trolley on the ground. The plurality of wheels comprises at least one actuator wheel that is configured to be driven by the at least one motor. The handle is connected to the frame and is configured to be held by a person. The plurality of sensor elements are integrated into the handle. The plurality of sensor elements are configured to generate detection signals when the handle is held by the person. The plurality of sensor elements are configured to provide the detection signals to the processing unit. The processing unit is configured to utilize the detection signals to drive the at least one actuator wheel via the at least one motor.

In this way, a trolley, or stroller, or pram, or supermarket trolley or kart is provided with an intuitive means to determine the support a person wants when using the trolley and electric motors can appropriately drive the wheel(s) of the trolley.

In other words, a tactile skin is applied to the handle of the trolley and this interface is used to determine the user’s intended direction of motion of the trolley and this information is used to drive wheel(s) of the trolley as required.

To put this another way, an intuitive means of user interaction is provided that allows a user to grasp the handle of the trolley or stroller anywhere and input continuous levels of desired support.

In an example, at least one of the plurality of sensor elements is integrated into a rear side of the handle.

Thus, when a user is pushing the trolley in order to move it forward, this is detected and the trolley motion can be supported in that direction.

In an example, at least one of the plurality of sensor elements is integrated into a front side of the handle.

In this way, when a user wishes to slow down the trolley, for example when going down a slope, this is detected as the user pulls back on the handle and the trolley or stroller motion can be slowed down through motorized drive as required.

In an example, utilization of the detection signals by the processing unit comprises a determination of at least one force being applied to the handle.

In an example, the processing unit is configured to determine one or more force being applied to the handle from the handle being held by one hand of the person. In an example, the processing unit is configured to determine two or more forces being applied to the handle from the handle being held by both hands of the person.

In an example, utilization of the detection signals by the processing unit comprises a determination of at least one torque being applied to the handle.

In an example, the processing unit is configured to determine one or more torque being applied to the handle from the handle being held by one hand of the person.

In an example, the processing unit is configured to determine two or more torques being applied to the handle from the handle being held by both hands of the person.

In this manner, as a natural way of interacting with a trolley or stroller whether being held with one hand or two hands is to apply forces and torques to the handle in order to move in straight lines and in curves, this information is acquired in a highly intuitive manner and used to drive wheels of the trolley as required.

In an example, the plurality of sensor elements are configured to generate a null signal when the handle is not being held by the person. The processing unit is configured to utilize the null signal to brake at least one of the plurality of wheels.

In an example, the null signal is utilized to stop the at least one actuator wheel from rotating.

In this manner, a simple braking functionality is provided.

In an example, the trolley comprises a wheel brake configured to stop at least one of the plurality of wheels from rotating. The null signal is utilized to apply the wheel brake.

In an example, by default the wheel brake is applied. The detection signals are used to release the brake. In this example, the normal state of the brake would be the locked state, brake applied, even without electric current flowing. At least one wheel is stopped from rotating, the trolley then cannot move. As soon as at least one of the sensors generates a sensor signal, the brake will be actively released or unlocked.

In an example, the plurality of sensor elements are covered by a deformable cover.

In an example, the plurality of sensor elements each have an inner surface positioned adjacent to a solid inner part of the handle.

In this manner, the sensor elements (tactile skin) is protected from environmental influences, with a soft human handle contact, enabling a user to easily scale the force being exerted. In an example, each sensor element of the plurality of sensor elements is a discrete 1 -dimensional force sensor.

In an example, the at least one actuator wheel comprises two actuator wheels rotationally connected to the frame on opposite sides of the frame to each other.

In an example, utilization of the detection signals by the processing unit comprises a determination of a first motor torque to be applied to a first of the two actuator wheels and a determination of a second motor torque to be applied to a second of the two actuator wheels.

Thus, overall forces and torque being applied to the handle is mapped to reference torques for the motor(s) to drive wheels of the trolley or stroller. This can be achieved through exploiting the kinematic relation between the actuated trolley wheels and the motion of the centre of the handle.

In a second aspect, there is provided a method of providing power to a trolley. The trolley comprises: a frame; a plurality of wheels; at least one motor; a handle; a plurality of sensor elements; and a processing unit; wherein the plurality of wheels are rotational connected to the frame and configured to support the trolley on the ground; wherein the plurality of wheels comprises at least one actuator wheel that is configured to be driven by the at least one motor; wherein the handle is connected to the frame and is configured to be held by a person; wherein the plurality of sensor elements are integrated into the handle. The method comprises the following steps:

a) generating detection signals with the plurality of sensor elements when the handle is held by the person;

b) providing the detection signals from the plurality of sensor elements to the processing unit; and

c) utilizing the detection signals by the processing unit to drive the at least one actuator wheel via the at least one motor.

In an example, step c) comprises determining at least one force being applied to the handle.

In an example, step c) comprises determining one or more force being applied to the handle from the handle being held by one hand of the person.

In an example, step c) comprises determining two or more forces being applied to the handle from the handle being held by both hands of the person. In an example, step c) comprises determining at least one torque being applied to the handle.

In an example, step c) comprises determining one or more torque being applied to the handle from the handle being held by one hand of the person.

In an example, step c) comprises determining two or more torques being applied to the handle from the handle being held by both hands of the person.

In an example, the method comprises step d) generating a null signal with the plurality of sensor elements when the handle is not being held by the person; and wherein the method comprises step e) utilizing the null signal by the processing unit to brake at least one of the plurality of wheels.

In an example, step e) comprises stopping the at least one actuator wheel from rotating.

In an example, the trolley comprises a wheel brake configured to stop at least one of the plurality of wheels from rotating, and wherein step e) comprises applying the wheel brake.

In an example, step c) comprises determining a first motor torque to be applied to a first one of the at least one actuator wheel and determining a second motor torque to be applied to a second one of the at least one actuator wheel.

According to another aspect, there is provided a computer program element controlling a trolley as previously described which, if the computer program element is executed by a processing unit, is adapted to perform the method steps as previously described.

According to another aspect, there is provided a computer readable medium having stored computer element as previously described.

The computer program element, can for example be a software program but can also be a FPGA, a PLD or any other appropriate digital means.

Advantageously, the benefits provided by any of the above aspects equally apply to all of the other aspects and vice versa.

The above aspects and examples will become apparent from and be elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be described in the following with reference to the following drawings:

Fig. 1 shows a schematic representation of a trolley;

Fig. 2 shows a method of providing power to a trolley;

Fig. 3 shows a schematic representation of a side view of a trolley handle; Fig. 4 shows a schematic representation of a top view of a trolley handle; Fig. 5 shows a schematic representation of forces being measured by sensor elements;

Fig. 6 shows a schematic representation of forces being measured by sensor elements;

Fig. 7 shows a schematic representation of trolley going up an incline;

Fig. 8 shows a schematic representation of a top view of a trolley; and Fig. 9 shows a schematic representation of a side view of an actuated wheel.

DETAIFED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows an example of a trolley 10. The trolley comprises a frame 20, a plurality of wheels 30, at least one motor 40, a handle 50, a plurality of sensor elements 60, and a processing unit 70. The plurality of wheels are rotational connected to the frame and configured to support the trolley on the ground. The plurality of wheels comprises at least one actuator wheel 80 that is configured to be driven by the at least one motor. The handle is connected to the frame and is configured to be held by a person. The plurality of sensor elements are integrated into the handle. The plurality of sensor elements are configured to generate detection signals when the handle is held by the person. The plurality of sensor elements are configured to provide the detection signals to the processing unit. The processing unit is configured to utilize the detection signals to drive the at least one actuator wheel via the at least one motor.

In an example, a battery as used for example in e-bikes can be used to power the at least one motor and to provide power for the processing unit and sensor elements.

According to an example, at least one of the plurality of sensor elements is integrated into a rear side of the handle. According to an example, at least one of the plurality of sensor elements is integrated into a front side of the handle.

According to an example, utilization of the detection signals by the processing unit comprises a determination of at least one force being applied to the handle.

According to an example, the processing unit is configured to determine one or more force being applied to the handle from the handle being held by one hand of the person.

According to an example, the processing unit is configured to determine two or more forces being applied to the handle from the handle being held by both hands of the person.

According to an example, utilization of the detection signals by the processing unit comprises a determination of at least one torque being applied to the handle.

According to an example, the processing unit is configured to determine one or more torque being applied to the handle from the handle being held by one hand of the person.

According to an example, the processing unit is configured to determine two or more torques being applied to the handle from the handle being held by both hands of the person.

According to an example, the plurality of sensor elements are configured to generate a null signal when the handle is not being held by the person; and wherein the processing unit is configured to utilize the null signal to brake at least one of the plurality of wheels.

According to an example, the null signal is utilized to stop the at least one actuator wheel from rotating.

According to an example, the trolley comprises a wheel brake (90) configured to stop at least one of the plurality of wheels from rotating, and wherein the null signal is utilized to apply the wheel brake.

According to an example, the plurality of sensor elements are covered by a deformable cover.

According to an example, the plurality of sensor elements each have an inner surface positioned adjacent to a solid inner part of the handle.

According to an example, each sensor element of the plurality of sensor elements is a discrete 1 -dimensional force sensor. According to an example, the at least one actuator wheel comprises two actuator wheels rotationally connected to the frame on opposite sides of the frame to each other.

According to an example, utilization of the detection signals by the processing unit comprises a determination of a first motor torque to be applied to a first of the two actuator wheels and a determination of a second motor torque to be applied to a second of the two actuator wheels.

Fig. 2 shows a method 100 of providing power to a trolley in its basic steps. The trolley comprises: a frame; a plurality of wheels; at least one motor; a handle; a plurality of sensor elements; and a processing unit; wherein the plurality of wheels are rotational connected to the frame and configured to support the trolley on the ground; wherein the plurality of wheels comprises at least one actuator wheel that is configured to be driven by the at least one motor; wherein the handle is connected to the frame and is configured to be held by a person; wherein the plurality of sensor elements are integrated into the handle. The method 100 comprises:

in a generating step 110, also referred to as step a), generating detection signals with the plurality of sensor elements when the handle is held by the person;

in a providing step 120, also referred to as step b), providing the detection signals from the plurality of sensor elements to the processing unit; and

in a utilizing step 130, also referred to as step c), utilizing the detection signals by the processing unit to drive the at least one actuator wheel via the at least one motor.

In an example, at least one of the plurality of sensor elements is integrated into a rear side of the handle.

In an example, at least one of the plurality of sensor elements is integrated into a front side of the handle.

According to an example, step c) comprises determining at least one force being applied to the handle.

According to an example, step c) comprises determining one or more force being applied to the handle from the handle being held by one hand of the person.

According to an example, step c) comprises determining two or more forces being applied to the handle from the handle being held by both hands of the person. According to an example, step c) comprises determining at least one torque being applied to the handle.

According to an example, step c) comprises determining one or more torque being applied to the handle from the handle being held by one hand of the person.

According to an example, step c) comprises determining two or more torques being applied to the handle from the handle being held by both hands of the person.

According to an example, the method comprises step d) generating 140 a null signal with the plurality of sensor elements when the handle is not being held by the person; and wherein the method comprises step e) utilizing 150 the null signal by the processing unit to brake at least one of the plurality of wheels.

According to an example, step e) comprises stopping the at least one actuator wheel from rotating.

According to an example, the trolley comprises a wheel brake configured to stop at least one of the plurality of wheels from rotating, and wherein step e) comprises applying the wheel brake.

According to an example, the wheel brake is configured to be applied as default state, wherein step c) comprises utilizing the detection signals by the processing unit to release the brake.

In an example, the plurality of sensor elements are covered by a deformable cover.

In an example, the plurality of sensor elements each have an inner surface positioned adjacent to a solid inner part of the handle.

In an example, each sensor element of the plurality of sensor elements is a discrete 1 -dimensional force sensor.

In an example, the at least one actuator wheel comprises two actuator wheels rotationally connected to the frame on opposite sides of the frame to each other.

According to an example, step c) comprises determining a first motor torque to be applied to a first one of the at least one actuator wheel and determining a second motor torque to be applied to a second one of the at least one actuator wheel.

The trolley and method of providing power to a trolley are now described in more detail with reference to Figs. 3-9. It is to be noted that reference to providing power to a trolley refers to the provision of power to one or more wheels of the trolley. Fig. 3 shows a side view of a handle of the trolley/stroller, which could also be a stroller or pram, supermarket trolley or other wheeled trolley that users push. In this specific example referred to with respect to Figs. 3-9 the trolley is being referred to is a stroller. Continuing with Fig. 3 the handle of the stroller has a solid core surrounded by a deformable cover with integrated force sensing cells or elements. The handle need not have a solid core, but could for example be a solid metal tube with a hollow centre. Thus, a conformable tactile skin is attached/integrated to the stroller handle. Tactile skin is integrated into the handle in an inner layer, thereby the sensor skin is protected from environmental influences. Furthermore, the outer layer results in a soft human handle contact and the user can easily scale the force he or she is exerting due to the soft outer cover and the sensor elements being mounted next to the solid inner core. The skin consists of a finite number of discrete one-dimensional for sensors (load cells). Due to the conformable material of the handle cover, exerted forces are distributed to the sensors and a small number of sensor elements are sufficient to achieve the required spatial resolution. Such tactile skins have been investigated in the domain of robotics in order to enable physical human robot control with multiple contact points, as well as for safety reasons - see for example: Cirillo, C; Ficuciello, F; Natale, C; Pirozzi, S; Villani, L: A conformable force/tactile skin for physical human-robot interaction, IEEE Robotics and Automation Letters, 1, 41-48, 2016.

Fig. 4 shows a top view of the handle of the stroller shown in Fig. 3, where there are 8 sensor elements. They can be other numbers of sensor elements, and here 8 is just a representative example. In Fig. 4, coordinate systems are defined, where a common frame H is depicted at the centre, and individual sensor frames S are depicted at the position of each sensor element. With the skin (sensor elements) mounted in a defined position and orientation, the overall force and torque exerted by the user can be obtained by summing up all individual sensor element forces. To this end, the force each sensor measures is transformed into a common coordinate frame, the coordinate system attached to the centre of the stroller handle with the z-axis pointing upwards, the y-axis pointing into the forward direction of the stroller and the X axis perpendicular to both of these axes, with this being a natural choice as depicted in Fig. 4.

Fig. 5 shows a top view of the stroller handle being held by two hands of the user, showing how individual forces measured by the sensor elements are accumulated in the common coordinate frame, and in this case forward motion and turning right is induced. Fig. 6 shows a top view of the stroller handle being held by one hand of the user, where the user is not only pushing but also twisting the hand in order to create a pure forward motion (no resulting torque about z-axis of common coordinate frame).

The individual wrench measured by each cell in the tactile skin in the local coordinate frame is denoted comprising forces and torques in all three directions in space. The orientation of the z-th local coordinate system with respect to the coordinate system attached to the handle is given by and the translation of the z-th sensor relative to the common coordinate frame is given by t _H ^l . The accumulation of all measured forces in the common coordinate frame is hence given by

In Fig. 5, the example is given in which the user pushes the stroller with two hands. While forces are exerted on all sensor elements on one side of the stroller handle, the forces are larger on the sensor elements on the left-hand side. As a consequence, the stroller moves forward and turns are right.

In the second example shown in Fig. 6, the stroller is only pushed with one hand. As the grasp is off centre, the hand has to be twisted in order to cancel the torque about the z-axis of the common coordinate frame if a pure forward motion is desired. To measure such types of user input, sensor elements are attached on both sides of the handle.

Control method to map user input to motor reference torques

To calculate the motor reference torques for each actuated stroller wheel, the force into the stroller forward direction and the torque about the z-axis of the handle coordinate frame are extracted, i.e.

To support the user and reduce the interaction forces at the handle, the stroller motors are used to generate an equivalent force and torque of

Where a > 0 is a gain factor that can be adjusted to tune the level of support. To maintain a constant speed of the stroller, the sum of user input force and support force have to match all resistance forces / _resistance (mainly downhill for some rolling resistance force), i.e.

For a = 0, support is deactivated and the user has to handle the full resistance force,/ user f resistance·

Fig. 7 shows the effect of the gain factor a, where on the left the user has to overcome the full downhill force as a = 0. Whilst, the stroller on the right a = 1 is used. Hence, the support force is the same as the user input force fuser. As the sum of fuser and / _support has to counteract the downhill force / mu _, the load on the user is reduced by 50%.

Thus, as depicted in Fig. 7 and with reference to the above equation, a gain factor of a = 1 results in / user 0.5 * f resistance, leading to the load on the user being reduced by 50%.

To implement the design support, the desired support force and torque are mapped to tangential forces at the left and right actuated stroller wheels as shown in Fig. 8. Fig. 8 shows the support force and torque as calculated from user input, with the equivalent tangential forces at actuated wheels also shown. Based on the distance of the actuated wheels to the y-axis of the handle coordinate frame, denoted as“b” in Fig. 8, the required tangential will forces are calculated as

Fig. 9 shows a side view of an actuated wheel, along with the calculated desired motor torque based on tangential force. Here, the radius of the actuated wheels (r _w ) is employed to map the tangential forces to the corresponding motor torques, i.e.

It is to be noted that supporting the user does not only reduce user load when going uphill on uneven terrain, because sensor elements also present on the front side of the handle and as such the system also assists the user in breaking when going downhill. As a safety and comfort measure, torque support is faded out on the motors above a certain speed level. Furthermore, mechanical brakes are engaged (through a separate brake or through locking of the actuator wheels by the motor) whenever no force is exerted on the stroller handle at all. Thereby, brakes are locked by default to prevent the stroller from running away. Only once the user touches the handle are the brakes released.

In another exemplary embodiment, a computer program or computer program element is provided that is characterized by being configured to execute the method steps of the method according to one of the preceding embodiments, on an appropriate trolley.

The computer program element might therefore be stored on a computer unit, which might also be part of an embodiment. This computing unit may be configured to perform or induce performing of the steps of the method described above. Moreover, it may be configured to operate the components of the above described apparatus and/or system. The computing unit can be configured to operate automatically and/or to execute the orders of a user. A computer program may be loaded into a working memory of a data processor. The data processor may thus be equipped to carry out the method according to one of the preceding embodiments.

This exemplary embodiment of the invention covers both, a computer program that right from the beginning uses the invention and computer program that by means of an update turns an existing program into a program that uses invention.

Further on, the computer program element might be able to provide all necessary steps to fulfill the procedure of an exemplary embodiment of the method as described above. According to a further exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, USB stick or the like, is presented wherein the computer readable medium has a computer program element stored on it which computer program element is described by the preceding section.

A computer program may be stored and/or distributed on a suitable medium, such as an optical storage medium or a solid state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems.

However, the computer program may also be presented over a network like the World Wide Web and can be downloaded into the working memory of a data processor from such a network. According to a further exemplary embodiment of the present invention, a medium for making a computer program element available for downloading is provided, which computer program element is arranged to perform a method according to one of the previously described embodiments of the invention.

It has to be noted that embodiments of the invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any

combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

In the claims, the word“comprising” does not exclude other elements or steps, and the indefinite article“a” or“an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.