CN111587205A

CN111587205A - Transport device, in particular a baby carriage, with mass estimation

Info

Publication number: CN111587205A
Application number: CN201880086888.1A
Authority: CN
Inventors: J.鲍尔; N.马丁; J.菲斯特; B.席林格; S.格罗
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-01-18
Filing date: 2018-11-15
Publication date: 2020-08-25
Also published as: WO2019141405A1; DE102018200784A1; EP3740414A1; JP2021511249A; KR20200104878A

Abstract

In the case of a transport device (100), in particular a baby carriage, having at least three wheels (116, 118, 120, 122) and having a handle (110) for a user, wherein at least one wheel (120, 122) of the at least three wheels is designed as a drive wheel (132, 134) which can be driven in an electric manner by means of an associated electric drive unit (140, 142) in order to enable at least partial electric support of the opening in an electric mannerAnd wherein the electric drive unit can be adjusted by means of a torque adjusting device (200, 202) assigned to the electric drive unit, and the transport device has a computing unit (400) for quality estimation of the transport device, at least one acceleration sensor (170, 172) is provided, and a test signal (T) can be applied to the torque adjusting device (200, 202)_S) Wherein the computing unit (400) is designed to determine the result at least as a function of the pass test signal (T)_S) Acceleration signal (y) generated at the transport device (100) and detected by at least one acceleration sensor (172)_1,2(t)) to determine the mass (m) of the transport device (100)_K）。

Description

Transport device, in particular a baby carriage, with mass estimation

Technical Field

The invention relates to a transport device, in particular a baby carriage, having at least three wheels and having a handle for a user, wherein at least one of the at least three wheels is designed as a drive wheel which can be driven in an electric manner by means of an associated electric drive unit in order to enable a manual pushing or pulling movement of the transport device by the user to be supported at least partially in an electric manner, and wherein the electric drive unit can be adjusted by means of a torque adjustment device associated with the electric drive unit, and the transport device has a computing unit for a quality estimation of the transport device. Furthermore, the invention relates to a method for estimating the mass of a transport device, in particular a baby carriage.

Background

Transport devices designed as strollers are known from the prior art, which have active support by a user in a push or pull operation via an electrically drivable drive wheel. In order to obtain the best support result, in particular to adjust the usually at least one electrically driven driving wheel of the rear axle of the buggy in a manner adapted to the user and to the load, it is crucial to know the current mass of the buggy in addition to exactly knowing the type of foundation on which the buggy is moving.

However, the mass of the pushchair is variable, in particular due to the varying equipment parts or accessories and/or the weight of at least one child to be accommodated in the pushchair. Furthermore, it is costly to detect the entire mass of the stroller including the wheels if the weight measurement should be made, for example, by means of a plurality of strain gauges, spring elements, etc., which are required for detecting slight weight-related deformations of the undercarriage of the stroller and for converting them into an electrical measurement signal proportional to the weight or mass. Furthermore, direct mass measurement at all wheel axles of the stroller by means of force sensors becomes costly not only in terms of the required wiring, but also, if necessary, in terms of wireless data transmission.

Disclosure of Invention

The invention relates to a transport device, in particular a baby carriage, having at least three wheels and having a handle for a user, wherein at least one of the at least three wheels is designed as a drive wheel which can be driven in an electric manner by means of an associated electric drive unit in order to enable a manual pushing or pulling operation of the transport device by the user to be supported at least partially in an electric manner. The electric drive unit can be regulated by means of a torque regulation device assigned to the electric drive unit, and the transport device has a calculation unit for a mass estimation of the transport device. At least one acceleration sensor is provided and a test signal can be applied to the torque control device, wherein the computing unit is designed to determine the mass of the transport device at least as a function of an acceleration signal generated by the test signal at the transport device and detected by the at least one acceleration sensor.

It is thus possible to detect the (total) mass of the transport device relatively accurately in real time or "on-line". In the context of the present description, the (total) mass is to be understood as the mass of the transport device including all accessories and the weight of at least one object or child to be transported by means of the transport device. It is possible to eliminate the otherwise necessary placement of a large number of weight sensors at different locations at the chassis of the transport device.

According to a preferred embodiment, the test signal is a sine-shaped or cosine-shaped torque signal. Due to the harmonic signal profile, the mathematical and digital complexity required for calculating the mass of the transport device is significantly simplified.

The electric drive unit preferably has an electric motor, in particular a brushless dc motor. This ensures a practically low-wear, substantially low-maintenance and excellently adjustable drive of the transport device.

The gearbox is preferably assigned to the electric drive unit. It is thus possible to flexibly adapt the torque of the electric motor to the requirements of the transport device. If necessary, a shifting device with at least one gear can be provided, in order to enable mountain operation of the transport device in addition to plain operation, for example.

In a further technically advantageous embodiment, the acceleration signal can be detected by means of at least one acceleration sensor essentially in the primary pushing or pulling direction of the transport device. Thus, the main movement direction of the transport device is first considered for the mass estimation.

According to a further advantageous embodiment, the mass of the transport device can be estimated by means of a frequency analysis implemented by the computing unit. In this connection, different numerical methods, such as discrete fourier transforms, can be used for calculating the quality.

The calculation unit for the frequency analysis preferably has a Goertzel filter. Thereby giving a particularly efficient numerical evaluation for quality estimation.

According to a technically advantageous development, the computing unit has a correlator for estimating the mass of the transport device. Thus, an evaluation method is provided which is proven and experienced from communication technology and radio technology.

The mass is preferably estimated in real time by means of a calculation unit. It is thus possible to very comfortably adjust the electrically supported push or pull operation of the transport device depending on the current situation.

According to one embodiment, at least two of the at least three wheels are designed as drive wheels, which can each be driven in an electric manner by means of at least one electric drive unit, and wherein the electric drive units can be adjusted independently of one another by means of a torque adjustment device assigned to the electric drive units. A symmetrical drive of the transport device is thus possible, wherein a so-called "diagonal tension (Schiefziehen)" in the push or pull operation of the transport device can be avoided.

Furthermore, the invention provides a method for estimating the mass of a transport device, in particular a baby carriage, having at least three wheels and having a handle for a user. At least one of the at least three wheels can be driven electrically as a drive wheel by means of an electric drive unit, which can be adjusted by means of a torque adjustment device assigned to the electric drive unit, in order to ensure that a manual pushing or pulling operation of the transport device by a user is supported at least partially electrically. A test signal for exciting the transport device in an oscillation technique is applied to the torque control device, and the mass of the transport device is estimated at least by evaluating the acceleration signal detected by the at least one acceleration sensor.

It is thereby possible to detect the current (total) mass of the transport means relatively accurately in real time without having to place a large number of weight sensors at the transport means.

In an advantageous further development of the method, the evaluation is carried out by a goertzel algorithm implemented by means of a computing unit. This ensures a numerically resource-saving or mathematically efficient digital implementation by means of the computing unit.

In the case of a further embodiment, the evaluation takes place by means of a correlation implemented by means of a computing unit. It is therefore possible to use the relevant methods which have been tested and proven for a long time, in particular in communication technology and radio technology.

Drawings

In the following description, the invention is explained in more detail on the basis of embodiments shown in the drawings. Wherein:

figure 1 shows a schematic side view of a transport device configured as a baby carriage,

figure 2 shows an electromechanical block diagram of the stroller of figure 1 with a calculation unit for mass estimation,

fig. 3 shows a schematic block diagram of the stroller of fig. 1 with a goertzel filter implemented by means of a computing unit, an

Fig. 4 shows a schematic block diagram of the stroller of fig. 1 with a correlator implemented by means of a calculation unit.

Detailed Description

Fig. 1 shows a transport device 100 according to the invention with integrated mass estimation. Diagrammatically and exemplarily, the transport device 100 is configured as a stroller and is hereinafter referred to as "stroller 100".

It is noted that the configuration of the transport device 100 as a stroller has only exemplary characteristics and should not be construed as limiting the invention. Thus, the transporter 100 may also be configured according to the type of any other transporter having a mass estimation, for example according to the type of wheelbarrow, cart, trash can. The stroller 100 preferably has a preferably foldable chassis 102, the chassis 102 having a bed or seat 104. The mattress 106 is preferably placed into the lounge or seat as a bolster for at least one child 108.

A handle 110 for a user, not shown, for example an ergonomic height-adjustable U-shaped handle, is preferably arranged at the chassis 102. By user force F_UActing on the U-shaped handle 110 automatically places the stroller 100 in a push or pull operation that is at most partially electrically supported, whereby the stroller 100 essentially follows a push on foundation (untergrudd) 114Or pull direction 112.

With a (total) mass m to be estimated or determined with sufficient accuracy_KThe stroller 100 here has only four wheels 116, 118, 120, 122 by way of example, only of which only the wheels 116, 120 located at the front with respect to the plane of the drawing are shown in a diagrammatic manner. Alternatively, the stroller 100 can also be constructed in a three-wheeled manner with one front wheel and two rear wheels, which can preferably be driven in an electrically powered manner. The stroller 100 preferably has at least three wheels 116, 118, 120, 122. Here, preferably two wheels are arranged at the rear axle 130 and one wheel is arranged at the front axle 128, but it is also possible to arrange two wheels at the front axle 128 and one wheel at the rear axle 130. Mass m of the stroller 100_KResulting in a gravitational force F_gSaid gravity acting vertically in the direction of the here merely exemplary flat foundation 114, wherein the value of the gravitational acceleration g is assumed to be about 9.81m/s²。

The two rear wheels 120, 122 are embodied here merely as an example as

drive wheels

132, 134, which can each be driven individually in an electrically driven manner by means of an

electric drive unit

140, 142. Of the two

drive wheels

132, 134, again only the first drive wheel 132 which is located at the front with respect to the drawing plane can be shown in a diagrammatic manner. The first drive wheel 132 may be driven by means of a first electric drive unit 140 and the second drive wheel 134 may be driven independently of the first drive wheel 132 by means of a second electric drive unit 142. Of the at least three wheels 116, 118, 120, 122, preferably at least one wheel 120, 122 is configured as a

drive wheel

132, 134. The at least one

drive wheel

132, 134 may preferably be driven electrically by means of at least one

electric drive unit

140, 142. Here, the at least one

drive wheel

132, 134 may be arranged at the front axle 128 and/or the rear axle 130.

The two

electric drive units

140, 142 are in the simplest case realized with

electric motors

150, 152, respectively, preferably to support the push or pull operation of the stroller 100 at most partially electrically. Preferably, a first gearbox 158 is connected downstream of the first electric motor 150 and a second gearbox 160 is correspondingly connected downstream of the second electric motor 152 for torque adaptation.

Additionally, both

electric drive units

140, 142 may be equipped with a mechanical clutch for interrupting the energy flow, a mechanical brake for supporting the electric deceleration process of the stroller 100 by the

electric drive units

140, 142, and a locking device. In order to ensure optimal adjustability, the two

electric motors

150, 152 are preferably realized with permanently excited synchronous machines or brushless direct current motors (so-called "brushless DC motors"). For the two

gearboxes

158, 160, the planetary gearbox is particularly taken into account because of its compact structural shape and the high speed increase and decrease ratios that can be achieved. The

electric drive units

140, 142 or the

electric motors

150, 152 with the

gear boxes

158, 160 respectively connected downstream thereof are connected in a rotationally fixed manner to the hubs of the

drive wheels

132, 134 of the stroller 100, which are not shown for better drawing visibility.

Torque control devices

200, 202 are preferably assigned to each

electric drive unit

140, 142. In the electrically, at most partially supported push or pull operation of the stroller 100, a speed change Δ v is obtained, which in turn leads to an acceleration a perpendicular to the foundation 114_zWherein the process is similar to "dive" when the rear wheel drive vehicle is accelerating or tail "lift" when the rear wheel drive vehicle is decelerating. The acceleration a in space in the primary push or pull direction of the stroller 100 is illustrated by a coordinate system 199_yAnd acceleration a_zOf (c) is performed.

Furthermore, the stroller 100 preferably has at least one first and one

second acceleration sensor

170, 172 for indirectly estimating the mass m according to the invention by means of the computing unit 400_K. The two

acceleration sensors

170, 172 are used here to initially detect the acceleration a occurring in the normal pushing or pulling operation of the stroller 100_y. The

acceleration sensors

170, 172 may be integrated in the

electric drive units

140, 142 of the two

drive wheels

132, 134.

Fig. 2 shows an electromechanical block diagram of the stroller 100 of fig. 1 with two

torque adjustment devices

200, 202, wherein the first torque adjustment device 200 is connected to the first electric drive unit 140. Phase (C)The second torque control device 202 is coupled to the second electric drive unit 142. The first electric drive unit 140 comprises a first electric motor 150, downstream of which a first gearbox 158 is connected. The second electric drive unit 142 is constructed in a corresponding manner, said second electric drive unit 142 having a second electric motor 152 with a subsequent second gearbox 160. The first electric drive unit 140 is coupled to the first drive wheel 132 of the stroller 100, while the second electric drive unit 142 is connected in a rotationally fixed manner to the second drive wheel 134 of the stroller 100. In this case, the mechanical driving force F generated by means of the two

electric drive units

140, 142_w1And F_w2Primarily on the two

drive wheels

132, 134 of the stroller 100.

According to the invention, a sinusoidal or cosine-shaped test signal T, only by way of example here, is applied to both

torque control devices

200, 202_SOr to use the test signal to operate both

torque modulation devices

200, 202. Other periodic signal profile variations, such as trapezoidal, triangular, rectangular or aperiodic, irregular curve profiles, are likewise possible. Alternatively or additionally, it is also possible to apply different test signals to the

torque control devices

200, 202. Based on test signals T using sine-or cosine-shapes therein_SHere, only exemplary and preferably periodic, temporary activation of the

torque control devices

200, 202 is performed, followed by the drive force F waiting in line on the

drive wheels

132, 134_W1,2Time-varying or harmonic vibration variation processes.

At the first and second link points 210, 212, the driving force F generated by the

electric drive units

140, 142_W1,2Superimposed with other forces occurring during operation of the stroller, such as user force F_UFrictional force F acting on the wheels of the stroller 100_R1,2And other external forces F_ext.1,2Wherein the user force is preferably divided into two user forces F gripping on both sides of the handle 110 of fig. 1 of the stroller 100_U1,2Wherein the above forces act simultaneously and in their complementary action on the regulation circuit 230, here representing or mapping the whole of the buggy 100. External forceF_ext.1,2Such as wind loads, forces exerted by pets tethered to the stroller 100, other children carried with the help of the trailer roller board, downhill forces, etc.

The first and second output signals 214, 216 of the two

link points

210, 212 are preferably fed to a control loop 230 representing the entire stroller 100, wherein a substantially purely sine-shaped or cosine-shaped test signal T is present_SIn the case of (1), the first output signal 214 corresponds to a signal according to the equation

Torque signal into regulation loop 230

And the second output signal 216 corresponds to a signal according to the equation

Torque signal fed into the regulation loop 230

。

The stroller 100 is preferably constructed by testing the signal T by utilizing preferred harmonics_STwo torque profiles resulting from the actuation of the two

torque control devices

200, 202

Or the output signals 214, 216 after the two link points are excited into respective mechanical (natural) oscillations. The resulting acceleration of the stroller 100 is preferably measured by means of at least two

acceleration sensors

170, 172 positioned at the stroller 100 in a suitable manner.

In this case, the test signal T is based on a test signal by means of a preferably sinusoidal or cosine shape_SExcitation of the stroller 100 by acceleration signals output by the two acceleration sensors 170,

172Numbers

220, 222 follow the equation

And equation

Wherein the phase shift in the equation

Respectively, by the action of the control loop 230. The acceleration signals 220, 222 determined by the two

acceleration sensors

170, 172 are then preferably fed to a preferably digital electronic computing unit 400 for estimating or calculating the ascertained mass m of the stroller_K。

Fig. 3 illustrates a schematic block diagram of the stroller 100 of fig. 1 with the goertzel filter 250 implemented by means of the calculation unit 400. The regulating circuit 230 is preferably implemented by means of a test signal T which is only exemplary sine-shaped or cosine-shaped_SThe resulting output signals 214, 216, which in the case of the sine-shaped or cosine-shaped excitation given here follow the equation, can be excited into corresponding mechanical oscillations

Said mechanical oscillations lead to mechanical accelerations that can be simply measured by means of acceleration sensors (see in

particular reference numerals

170, 172 of fig. 2) due to the physical conditions of the regulation loop that maps the whole of the stroller 100. These accelerations are measured by at least two acceleration sensors (see in

particular reference numerals

170, 172 in fig. 2) and are transmitted as acceleration signals 220, 222 to the computing unit 400 for further evaluation, wherein the time course of the accelerations in the situation (konstein) described here follows at least approximately the equation

。

Furthermore, by means of the calculation unit 400, the digital goertzel filter 250 is implemented on the basis of a so-called goertzel algorithm, which provides a maximum acceleration value 252 or a discrete maximum acceleration value y₀. The goertzel algorithm is sufficiently familiar to the person skilled in the art of regulation technology that a more detailed description of the mathematical properties of the goertzel algorithm is to be dispensed with here for the sake of brevity of description.

From a maximum acceleration value y₀Medium and known maximum torque value u₀Together in a further processing stage 254 of the calculation unit 300, preferably according to a formula

Determining an estimated (total) mass m of a stroller_KBecause of other formulae

And equation of torque

It is suitable to derive from these, by simple deformation and insertion, an equation for determining the inertia of the mass

。

At the same time, the still reasonable calculation unit still needs to solve the problem of determining the mass m of the stroller 100 in real time or online, in contrast to other known methods for frequency analysis, such as discrete fourier transformation_KAt a digital or mathematical cost, the goertzel algorithm or the goertzel filter 250 technically implemented by said goertzel algorithm can be applied to the mass m of the stroller 100_KA sufficiently accurate determination or estimation is made.

Fig. 4 shows a schematic illustration of the stroller 100 of fig. 1 with a correlator 350 implemented by means of the calculation unit 400 of fig. 1An illustrative block diagram. By passing test signal T_SThe

torque control devices

200, 202 of fig. 1, which are applied and are likewise not shown here, can be dependent on a relationship

The first torque signal 300 is used to excite the control loop 230, which represents the stroller 100 again, from which the equation is derived on the output side

A first acceleration signal 302 is derived. Furthermore, by means of the test signal T_SAccording to the equation

The phase-shifted second torque signal 304 is generated in the same manner, however, it is phase-shifted by about 90 ° relative to the first torque signal 300.

In contrast to the goertzel filter of fig. 3, in order to determine the (total) mass m of the stroller 100_KThe calculation unit 400 here preferably has a correlator 350, which is illustratively constructed with first and

second multipliers

352, 354 and first and second

mean analyzers

356, 358. A first mean analyzer 356 is connected downstream of the first multiplier 352 and a second mean analyzer 358 is connected downstream of the second multiplier 354.

After passing through the regulation loop 230, the first torque signal 300 is preferably in accordance with the equation

A first acceleration signal 302 is generated, which is supplied in parallel to the two

multipliers

352, 354 of the correlator 350. Furthermore, the first torque signal 300 is preferably supplied to a first multiplier 352, and the phase-shifted second torque signal 304 is supplied to a second multiplier 354. The product 360 of the first multiplier 352 reaches a first mean analyzer 356 and the second multiplicationThe product 362 of the generator 354 is fed to the second mean analyzer 358.

Correlated output signal from first average analyzer 356

And the correlation output signal of the second average analyzer 358

Starting from, in which the variable T_PIn each case corresponding to a constant cycle time, the mass m of the stroller 100 to be estimated or determined sufficiently accurately can be derived, preferably by means of the computing unit 400, from the equations (1) to (5) described below_K：

。

Thus, by means of the correlator 350 implemented technically by the digital computation unit 400, it is possible to estimate or determine the mass m of the stroller 100 by means of correlation methods known and proven in particular from communication technology_KSaid related methods are also well known to the person skilled in the art of regulation working.

For estimating the mass m of a transport device, which is designed as a baby carriage in an exemplary manner, according to the invention_KIn the case of the method of (2), the test signal T is preferably first applied to the

torque control devices

200, 202 of fig. 1_SFor the purpose of mechanical oscillation excitation of the stroller 100 of fig. 1. At least by evaluating the acceleration signal y detected by the at least one

acceleration sensor

170, 172 of fig. 1_1,2(t) to estimate the mass m of the stroller 100_K. However, it is also possible at least by evaluating the acceleration signal y detected by the at least two

acceleration sensors

170, 172 of fig. 1_1,2(t) to estimate the mass m of the stroller 100_K. In a digital electronic meter by means of figure 1In the case of the calculation unit 400, the mass m of the stroller 100 is calculated either by the so-called goertzel algorithm or by a correlation, respectively_KDetermination or estimation of.

Alternatively, a large number of other acceleration sensors may be provided at the stroller 100 of fig. 1, which detect acceleration in a direction different from the primary push or pull direction of the stroller 100. Furthermore, sensors for measuring the rotational acceleration around all axes of the space may also be provided.

Claims

1. A transport device (100), in particular a baby carriage, having at least three wheels (116, 118, 120, 122) and having a handle (110) for a user, wherein at least one wheel (120, 122) of the at least three wheels (116, 118, 120, 122) is configured as a drive wheel (132, 134) which can be driven in an electrically powered manner by means of an assigned electric drive unit (140, 142) in order to enable a manual pushing or pulling movement of the transport device (100) by the user to be supported at least partially in an electrically powered manner, and wherein the electric drive unit (140, 142) can be adjusted by means of a torque adjustment device (200, 202) assigned to the electric drive unit, and the transport device (100) has a calculation unit (400) for a quality estimation of the transport device (100), characterized in that, at least one acceleration sensor (170, 172) is provided and a test signal (T) can be applied to the torque control device (200, 202)_S) Wherein the calculation unit (400) is designed to determine the result at least as a function of the passing of the test signal (T)_S) An acceleration signal (y) generated at the transport device (100) and detected by the at least one acceleration sensor (172)_1,2(t)) to determine the mass (m) of the transport device (100)_K）。

2. Transport unit according to claim 1, characterized in that the test signal (T)_S) Torque signal (u) being sinusoidal or cosine-shaped_1,2(t)）。

3. Transport device according to claim 1 or 2, characterized in that the one electric drive unit (140, 142) has an electric motor (150, 152), in particular a brushless dc motor.

4. Transport device as claimed in any of the foregoing claims, characterized in that the one electric drive unit (140, 142) is assigned a gearbox (158, 160).

5. Transport unit according to claim 4, characterized in that an acceleration signal (y) can be detected substantially in the primary push or pull direction (112) of the transport unit (100) by means of the at least one acceleration sensor (170, 172)_1,2(t)）。

6. Transport unit according to any of the preceding claims, characterized in that the mass (m) of the transport unit (100) can be estimated by means of a frequency analysis implemented by the calculation unit (400)_K）。

7. The transport device according to claim 6, characterized in that the calculation unit (400) has a Goertzel filter (250) for frequency analysis.

8. A transporter as claimed in claim 7, characterized in that the computing unit (400) has a correlator (350) for estimating the mass (m) of the transporter (100)_K）。

9. The transportation device according to any one of the preceding claims, characterized in that the mass (m) is estimated in real time by means of the calculation unit (400)_K）。

10. Transport device as claimed in any of the preceding claims, characterized in that at least two wheels (120, 122) of the at least three wheels (116, 118, 120, 122) are configured as drive wheels (132, 134) which can each be driven in an electric manner by means of at least one electric drive unit (140, 142), and wherein the electric drive units (140, 142) can be adjusted independently of one another by means of torque adjustment devices (200, 202) which are each assigned to the electric drive unit.

11. Method for estimating the mass (m) of a transport device (100), in particular a baby carriage_K) The transport device having at least three wheels (116, 118, 120, 122) and having a handle (110) for a user, wherein at least one wheel (120, 122) of the at least three wheels (116, 118, 120, 122) is driven in an electric manner as a drive wheel (132, 134) by means of an electric drive unit (140, 142) in order to ensure that a manual pushing or pulling operation of the transport device (100) by the user is supported at least partially in an electric manner, wherein the electric drive unit (140, 142) can be adjusted by means of an assigned torque adjustment device (200, 202), characterized in that a test signal (T) is applied to the torque adjustment device (200, 202)_S) For exciting the transport device (100) in an oscillatory manner, and at least by evaluating an acceleration signal (y) detected by at least one acceleration sensor (170, 172)_1,2(t)) to estimate the mass (m) of the transportation device (100)_K）。

12. The method according to claim 11, characterized in that said evaluation is performed by a goertzel algorithm implemented by means of a calculation unit (400).

13. The method according to claim 11, characterized in that the evaluation is performed by means of a correlation implemented by means of a calculation unit (400).