WO2021069323A1

WO2021069323A1 - Transport device, in particular a pram comprising an electric drive unit

Info

Publication number: WO2021069323A1
Application number: PCT/EP2020/077646
Authority: WO
Inventors: Karolina BACH; Alexander SISIN; Pierre Nonnenmacher; Bertram SCHILLINGER; Kai-Michael ULLRICH; Stefan Groh
Original assignee: Robert Bosch Gmbh
Priority date: 2019-10-12
Filing date: 2020-10-02
Publication date: 2021-04-15
Also published as: DE102019215706A1

Abstract

The invention relates to a transport device (100), in particular a pram, having a chassis (101) and a handle (110) for a user, wherein at least two drive wheels (132, 134), each drivable by means of an associated electric drive unit (140, 142), are arranged on the chassis (101) for at least partially assisting a manual pushing or pulling operation of the transport device (100) by the user. The associated electric drive units (140, 142) can be controlled by means of a control device (190) associated with the transport device (100). A safety device (192) is associated with the control device (160), said safety device being designed to deactivate the at least two drive wheels (132, 14) if the two drive wheels (132, 134) carry out a movement that questions the safety.

Description

description

title

Transport device, especially a stroller with an electric drive unit

State of the art

The present invention relates to a transport device, in particular a stroller, with a chassis and with a handle for a user, with at least two drive wheels each driven by an associated electric drive unit to at least partially support a manual pushing or pulling operation of the transport device on the chassis the user are arranged, and wherein the associated electrical drive units are controlled by means of a control device associated with the transport device.

Transport devices designed as strollers are known from the prior art, which have electric drives for active Schiebeun support of a user. For safety reasons, a drive system of the transport device, in particular such a pram, can be designed to detect a critical state of the transport device. For example, an absence of a user or a letting go of the stroller can be determined so that accidents caused by a stroller moving automatically and in an uncontrolled manner can at least essentially be prevented. For example, electrified baby carriages are known in which the presence of a user can be detected by at least one force sensor.

Disclosure of the invention The present invention relates to a transport device, in particular a stroller, with a chassis and with a handle for a user, with at least two drive wheels each driven by an associated electric drive unit to at least partially support a manual pushing or pulling operation of the transport device on the chassis the user are arranged, and wherein the associated electrical drive units are controlled by means of a control device associated with the transport device. The control device is assigned a safety device which is designed to deactivate the at least two drive wheels when a safety-critical behavior of the at least two drive wheels occurs.

The invention thus makes it possible to provide a transport device in which the safety device can safely and reliably determine a critical state that may possibly occur during operation. Thus, at least an unintentional acceleration of the transport device can easily and uncomplicatedly be detected and at least largely prevented.

The safety device preferably has a wheel slip detection unit which is designed to detect a spinning of the at least two drive wheels. In this way, a spinning drive wheel can be switched off in a simple and straightforward manner, whereby dangerous situations due to the spinning drive wheel can be avoided. In particular, the transport device can be prevented from skidding.

The wheel slip detection unit detects a spinning of the at least two drive wheels as a function of a transport device acceleration difference and assigned threshold values. Detection can thus be made possible in a simple manner.

According to one embodiment, the transport device acceleration difference is a difference between a determined acceleration of a given benen drive wheel of the at least two drive wheels and a determined acceleration of the transport device. Thus, a safe and reliable transport device acceleration difference can be determined.

The safety device is preferably assigned a detection unit which is designed to detect whether the at least two drive wheels are lifted from a respective underground or are arranged on the respective underground. In this way, a dangerous situation due to a false detection and an associated, undesired acceleration of the transport device can be prevented in a simple and uncomplicated manner.

The detection unit preferably determines, depending on an angular acceleration of the transport device and an angular acceleration assigned to one of the at least two drive wheels, whether at least one of the at least two drive wheels is lifted from the respective ground or is arranged on the respective ground. A lifting of one of the at least two drive wheels from the ground can thus be safely and reliably detected.

A drive wheel lifted from the respective ground is preferably detected as a function of a calculated angular acceleration of the transport device and a measured standstill of at least one drive wheel. In this way, it is easy and uncomplicated to detect whether a drive wheel has lifted off the ground.

According to one embodiment, a drive wheel arranged on the respective ground is detected when a measured angular acceleration of the transport device corresponds to a calculated angular acceleration of the transport device. A suitable detection can thus be made possible in a simple manner.

A sensor device with a first sensor element and at least one second sensor element is preferably provided, wherein the first sensor element ement detects an angular acceleration of the transport device and the at least one second sensor element detects an angular acceleration of an associated drive wheel. An angular acceleration of the transport device and an angular acceleration of an assigned drive wheel can thus be detected safely and reliably.

According to one embodiment, the first sensor element is a gyroscope sensor and / or the at least one second sensor element is a rotor position sensor. Suitable sensor elements can thus be provided in a simple manner.

Brief description of the drawings

The invention is explained in more detail in the following description with reference to Ausführungsbei shown in the drawings. Show it:

Fig. 1 is a side view of a transport device designed as a stroller with a control device to which a safety device and a sensor unit are assigned,

Fig. 2 is a schematic representation of the safety device of Fig. 1 with a wheel slip detection unit and two further detection units for determining whether the drive wheels are arranged on the ground,

3 shows a schematic illustration of an exemplary structure of the wheel slip detection unit from FIG. 2,

Fig. 4 is a side view of the transport device designed as a stroller of Fig. 1 with the drive wheels lifted from the ground, and Fig. 5 is a schematic representation of the angular accelerations acting on the transport device of Fig. 1 and are arranged on the ground.

Description of the exemplary embodiments 1 shows a transport device 100, which is designed as a stroller 100 by way of example and is referred to below as a “stroller 100”. The children's carriage 100 preferably has a chassis 102 which can be folded up like scissors, for example, and on which a lounger or seat pan 104 is arranged as an illustration. A handle 110 is generally arranged on the chassis 102, which is preferably used as a height-adjustable, U-shaped bracket or as a handle bar for pushing or pulling the stroller 100 in the direction of a double arrow 112 on a surface 114 by an in the drawings is trained user not shown. A pulling operation of the stroller 100 is exemplified by a dashed section of the double arrow 112, while a corresponding pushing operation of the stroller 100 is indicated by a portion of the double arrow 112 shown with a solid line.

The stroller 100 preferably has at least three wheels. Two wheels are preferably arranged on a rear axle 130 and one wheel on a front axle 128, but two wheels can also be arranged on the front axle 128 and one wheel on the rear axle 130. On the chassis 102, four wheels 120, 122, 124, 126 are provided here by way of example, the wheels 120, 124 being only visible here and further forward in relation to the plane of the drawing, the two wheels 122, 124 being further back in relation to the plane of the drawing. 126 cover each. The wheels 120, 122 are preferably on both sides of the front axle 128 and the wheels 124, 126 are attached to the rear axle 130 of the chassis 102 of the stroller 100.

Of the at least three wheels 120, 122, 124, 126, at least one wheel is preferably designed as a drive wheel 132, 134. The at least one drive wheel 132, 134 can preferably be driven by an electric motor by means of at least one electric drive unit 140, 142. The at least one drive wheel 132, 134 can be arranged on the front axle 128 and / or the rear axle 130. At least two wheels are preferably designed as drive wheels 132, 134. The two wheels 124, 126 assigned to the rear axle 130 are preferably each designed as drive wheels 132, 134, which are preferably used to at least partially support the manual pushing or pulling operation of the stroller 100 by the user.

The drive wheels 132, 134 can each preferably be driven independently of one another by means of an electric drive unit 140, 142 directly or indirectly via a gear (not shown) and controlled by means of a control device 190 assigned to the stroller 100. The control device 190 is preferably assigned a safety device 192 which is designed to deactivate at least one of the at least two drive wheels 132, 134 when the stroller 100 behaves in a safety-critical manner. The safety device 192 preferably deactivates all drive wheels associated with the stroller 100, in the present exemplary embodiment both drive wheels 132, 134.

The safety device 192 preferably has a wheel slip detection unit (210 in FIG. 2) which is designed to detect a spinning of at least one of the at least two drive wheels 132, 134. Alternatively or optionally, the safety device 192 is assigned a detection unit (220, 230 in FIG. 2), which is designed to detect whether at least one of the at least two drive wheels 132, 134 is lifted from a respective subsurface or on the respective Is arranged underground.

In addition or as an option, a sensor device 180 is provided to which at least one sensor element is assigned. Illustratively, the sensor device 180 is assigned a first sensor element 182 and at least one second sensor element 184. The first sensor element 182 is preferably designed to detect an angular acceleration (w _z in FIG. 5, oo _y in FIG. 4) of the transport device or the stroller 100 and the at least one second sensor element 184 is designed to detect an angular acceleration (OJ _I , 002 in FIG. 4) of an associated drive wheel 132, 134. According to one embodiment, the first sensor element 182 is a gyroscope sensor and / or that at least one second sensor element 184 is a rotor position sensor. Deviating from the positioning of the sensor element 182 on the reclining or seat pan 104 of the stroller 100 and the sensor element 184 in the area of a drive wheel 132 of the rear axle 130, these can also be positioned on the chassis 102 or at any other point on the stroller 100, be arranged.

Deviating from the embodiment of a classic stroller 100 shown here merely as an example, it can also be designed as a sports cart or buggy or as a twin or tandem stroller or as a two-seater buggy. A right-angled coordinate system 199 with an x-axis, y-axis and a z-axis illustrates the position of all components in space. The empty, unoccupied stroller preferably has a constant mass m, which results in a maximum effective weight force of Fg = m * g in the case of the horizontal base 114, an angle of inclination of the base 114 being essentially equal to 0 °.

It should be noted that the design of the transport device 100 as a stroller is only an example and is not to be understood as a restriction of the invention. Thus, the transport device 100 can also be designed in the manner of any other transport device which has a subsurface determination according to the invention, e.g. in the manner of a wheelbarrow, a hand truck or a garbage can.

FIG. 2 shows an exemplary structure of the safety device 192 from FIG.

1. The safety device 192 preferably has a wheel slip detection unit 210 which is designed to detect a spinning of at least one of the preferably at least two drive wheels 132, 134. Alternatively or optionally, the safety device 192 is assigned a detection unit 220 and a detection unit 230, which are designed to detect whether at least one of the preferably at least two drive wheels 132, 134 is lifted from a respective ground 114 of FIG respective underground is arranged. The detection unit 220 preferably detects whether the drive wheels 132, 134 are arranged on the ground 114 are. Furthermore, the recognition unit 230 recognizes whether the drive wheels 132, 134 have lifted off the ground 114.

If the wheel slip detection unit 210 detects a wheel slip, a deactivation unit 240, which is designed to deactivate the drive wheels 132, 134, is preferably activated. Optionally, after a wheel slip has been detected, the detection unit 230 can be activated, which checks whether the drive wheels 132, 134 have lifted off the ground 114, i.e. are spaced apart from the ground and therefore a wheel slip is present. If no wheel slip is detected, an activation unit 245 is activated, which is designed to activate the drive wheels 132, 134.

If the detection unit 230 detects that the drive wheels 132, 134 have lifted off the underground 114, the deactivation unit 240 is activated. The deactivation unit 240 is formed for deactivating the drive wheels 132, 134. If no lifting of the drive wheels 132, 134 is detected, the drive wheels 132, 134 are activated by the activation unit 245.

If the detection unit 220 detects that the drive wheels 132, 134 are arranged on the ground 114, the activation unit 245 is activated. Optionally, after detecting the arrangement of the drive wheels 132,

134, the wheel slip detection unit 210 is activated on the ground 114, which checks whether a wheel slip is present. If no arrangement of the drive wheels 132, 134 on the ground 114 is detected, then a check is carried out by the detection unit 230 as to whether the drive wheels 132, 134 have lifted off the ground 114.

FIG. 3 shows an exemplary structure of the wheel slip detection unit 210 from FIG. 2. Preferably, the wheel slip detection unit 210 detects depending on a transport device acceleration difference 321 or

Aa wagon wheel and associated threshold values 331 Aa. _{Carriage swing} u _e Durchdre a hen at least one of the at least two drive wheels 132, 134. The transport device 321 is preferably a differential acceleration difference between a first determined acceleration 311 of a predetermined drive wheel 132, 134 of the at least two drive wheels 132, 134 and a second determined acceleration 313 of the transport device 100. The first determined acceleration 311 is preferably a _wheel acceleration a wheel, which is preferably provided by a position sensor 310 , for example the second sensor element 184, is determined. Furthermore, the second determined acceleration 313 is a vehicle acceleration a _BMI , which is preferably measured by an acceleration sensor 312, for example the first sensor element 182. The acceleration due to gravity g is preferably subtracted to determine the pure car acceleration a _car . The transport device acceleration difference 321 or a _{cart wheel} is preferably calculated in an operator 320 as a function of the determined acceleration 311 of a drive wheel 132, 134 and the determined acceleration 313 of the transport device 100. The following relationships exist:

The pitch angle cp is preferably calculated using a complementary filter. It should be noted that the pitch angle cp also contains the wheel speed, which must be extracted from the signal from the acceleration sensor. Incorrect wheel acceleration leads to an incorrect incline angle cp. An incorrectly rotating drive wheel 132, 134 therefore also influences the angle calculation, which in turn is used for wheel slip detection. Since the dynamics of the drive wheel 132, 134 are higher than the angle calculation, it still works.

Subsequently, a comparison is carried out of the transport means acceleration difference 321 and a _{wagon wheel} with a predetermined threshold 331 ct-car sc _h we _ll e in a relative operator 340. The operator 340 a status, it is determined whether the transport device acceleration difference 321 indicates idling of the drive wheel 132, 134 or not. The threshold 331 Aa _{carriage pivot} ii _e is determined in a Schwellwertermittlungseinheit 330th Preferably, a y value can describe a permitted deviation of the two calculated accelerations a _wheel , a _car , and an x value describes a wheel angular speed. Here, the threshold value 331 ciwagen-schweiie ^e i ⁿ the product of the two deviations.

If the transport device acceleration difference 321 is too high, ie greater than the threshold value 331, a deactivation signal 342 is sent to an angle calculation unit 360, which is designed to stop the angle calculation until the wheel is stopped. If the transport device acceleration difference 321 is not too high, that is to say less than the threshold value 331, an activation signal 341 is sent to a reset function 350.

Fig. 4 shows the transport device 100 of FIG. 1 when the drive wheels 132, 134 are lifted off the ground 114 by a lifting angle a. FIG. 4 shows the angular accelerations w1 and w2 which are assigned to the drive wheels 132, 134 and are illustrative are drawn in the direction of travel or counterclockwise. In addition, an angular acceleration oo _{y of} the transport device 100 is shown, which preferably acts in the transverse direction of the transport device 100.

The detection unit 220 and / or 230 of FIG. 2 preferably determines as a function of an angular acceleration (oo _y w _z ίh Fig. 5) of the transport device 100 and an angular acceleration w1, w2 assigned to one of the at least two drive wheels 132, 134, whether at least one of the at least two drive wheels 132, 134 is lifted from the respective underground 114 or is arranged on the respective underground. A drive wheel 132, 134 lifted from the respective ground 114 is detected as a function of a calculated angular acceleration oo _{y of} the transport device 100 and a measured standstill of at least one drive wheel 132, 134.

Mathematically, when the drive wheels 132, 134 lift off the ground 114, the following criteria apply:

If there is an angular acceleration w _n , preferably a negative angular acceleration ü) _y , without the drive wheels 132, 134 moving, or the angular acceleration w1, w2 is less than a minimum wheel speed n _mm , the transport device 100 can only move from the ground 114 be lifted.

Fig. 5 shows the transport device of FIG. 4 and illustratively the preferably four wheels 120-126, the two wheels 120, 122 being designed as castors for steering the transport device 100 and the wheels 124, 126 being designed as drive wheels 132, 134 . The drive wheels 132, 134 are arranged in the longitudinal direction 599 at a distance I from a center of gravity S of the transport device 100 away. Furthermore, the two drive wheels 132, 134 are spaced apart from one another by a distance D in the transverse direction 598 of the transport device 100. A pivot point 597 is preferably arranged centrally between the two drive wheels 132, 134.

A drive wheel 132, 134 arranged on the respective subsurface is preferably detected when an angular acceleration w _z, preferably measured by the first sensor element 182 of FIGS. 1 and 4, is measured by the transport device 100 and a calculated angular acceleration ü _{z is calculated by} the transport device 100 corresponds. The calculated angular acceleration ü _{z calculated by} the transport device 100 is determined as a function of the angular acceleration w1 and w2 of the drive wheels 132, 134 and the distance D determined by the associated at least one second sensor element 184. The angular acceleration w1 is assigned to the drive wheel 132 and the angular acceleration w2 to the drive wheel 134. The sensor element 184 preferably determines a respective wheel speed n, a wheel speed being assigned to the drive wheel 132 and a wheel speed n2 being assigned to the drive wheel 134. The following applies: w _± = 2 * p * n _± w ₂ = 2 * p * ^h ₂

If one drive wheel, or both drive wheels 132, 134, are raised from the ground 114, then they preferably have different directions of rotation which, however, do not match the measured values of the sensor elements 182, 184. Here, the angular acceleration w1 would be a movement of the

Causing the transport device 100 in the direction of an arrow 502 to the illustrative top right and loading of the transport device 100 by the angular acceleration w2 would cause the transport device 100 to move in the direction of an arrow 504 to the illustrative bottom left. In addition, however, the guide rollers 120, 122 would cause the transport device to move

100 in the direction of an arrow 501 towards the illustrative top right.

Claims

Expectations

1. Transport device (100), in particular a stroller, with a Fahrge alternate (102) and with a handle (110) for a user, wherein on the chassis (102) at least two each by means of an associated electrical drive unit (140, 142) can be driven Drive wheels (132, 134) for at least partial support of a manual pushing or pulling operation of the transport device (100) by the user are arranged, and the associated electric drive units (140, 142) by means of a control device (100) associated with the transport device (100). 190) are controllable, characterized in that the control device (190) is assigned a safety device (192) which is designed to activate the at least two drive wheels (132, 134) if the behavior of the at least two drive wheels (132, 134) is critical to safety ) to deactivate.

2. Transport device according to claim 1, characterized in that the safety device (192) has a wheel slip detection unit (210) which is designed to detect spinning of the at least two drive wheels (132, 134).

3. Transport device according to claim 2, characterized in that the

Wheel slip detection unit (210) detects spinning of the at least two drive wheels (132, 134) as a function of a transport device acceleration difference (321) and associated threshold values (331).

4. Transport device according to claim 3, characterized in that the transport device acceleration difference (321) is a difference between see a determined acceleration (311) of a predetermined drive wheel (132, 134) of the at least two drive wheels (132, 134) and a he determined acceleration (313) of the transport device (100).

5. Transport device according to one of the preceding claims, characterized in that the safety device (192) is assigned a detection unit (220, 230) which is designed to recognize whether the at least two drive wheels (132, 134) of a respective one Subsurface are raised or are arranged on the respective subsurface.

6. Transport device according to claim 5, characterized in that the detection unit (220, 230) as a function of an angular acceleration (uj _y , W _z ) of the transport device (100) and one of the at least two drive wheels (132, 134) associated angular acceleration (OJ _I , 002) determines whether at least one of the at least two drive wheels (132, 134) is lifted from the respective ground or is arranged on the respective ground.

7. Transport device according to claim 5 or 6, characterized in that a detection of a drive wheel (132, 134) lifted from the respective ground as a function of a calculated angular acceleration (uj _y ) of the transport device (100) and a measured standstill of at least one drive wheel (132 , 134) takes place.

8. Transport device according to claim 5 or 6, characterized in that a detection of a drive wheel (132, 134) arranged on the respective underground occurs when a measured angular acceleration of the transport device (100) corresponds to a calculated angular acceleration of the transport device (100).

9. Transport device according to one of the preceding claims, characterized in that a sensor device (180) with a first sensor element (182) and at least one second sensor element (184) is provided, the first sensor element (184) having an angular acceleration (W _z , oo _y ) of the transport device (100) is detected and the at least one second sensor element (184) detects an angular acceleration (wi, 002) of an associated drive wheel (132, 134).

10. Transport device according to claim 9, characterized in that the first sensor element (182) is a gyroscope sensor and / or the at least one second sensor element (184) is a rotor position sensor.