AU2015295832B2

AU2015295832B2 - Device and method for generating a gradient value

Info

Publication number: AU2015295832B2
Application number: AU2015295832A
Authority: AU
Inventors: Daniel Baumgaertner; Gregor Dasbach; Jan Jordan
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-07-30
Filing date: 2015-05-12
Publication date: 2017-09-07
Anticipated expiration: 2035-05-12
Also published as: AU2015295832A1; JP2017524940A; GB2546186A; WO2016015890A1; CN106660606A; CN106660606B; JP6355822B2; DE102014214965A1; GB201703066D0; DE102014214965B4

Abstract

The invention relates to a method for generating a gradient value, comprising the following steps: At least two pressure variables are detected by means of a pressure sensor (DS) and at least one acceleration variable is detected by means of an acceleration sensor (BS) and a first gradient value is generated in accordance with the at least two pressure variables and a second gradient value is generated in accordance with the at least one acceleration variable. The method also comprises the additional step of outputting the first or second gradient value in accordance with the amount of the quotients of both gradient values.

Description

Device and Method for Generating a Gradient Value

Field of the Invention

The present invention relates to a method and a device for generating a gradient value. 5 Prior Art

Prior art discloses methods for determining gradient values relating e.g. to the gradient of a plane beneath a bicycle. Also known in the art are devices for processing measured signals, generated on a bicycle, that can be used to infer the gradient of a plane beneath the bicycle.

For example, DE 40 11 560 A1 deals with a device that uses a combination of an electronic io odometer and a pendulum to detect and display the altitude differences traversed by a vehicle, and the vehicle’s inclination.

Disclosure of the Invention

The invention relates to a method and a device for generating a gradient value, in which at least two pressure quantities and at least one acceleration quantity are detected is independently of each other. Then, a first gradient value is generated as a function of the at least two pressure quantities, and a second gradient value is generated as a function of the at least one acceleration quantity. The gradient value can be used as a base value for further data processing. To perform the method, the device has a processing unit, which outputs a gradient quantity as a signal representing the first or second gradient value, depending on 2o the magnitude of the quotient of the two gradient values. The two or more pressure quantities can be detected by means of a barometric sensor. The acceleration quantity or quantities can be detected by means of an acceleration sensor, preferably a MEMS sensor.

The invention also relates to a bicycle, in particular an electric bicycle. This bicycle has a device suitable for generating a gradient value. The device is preferably suitable for 25 performing the method of the present invention, and is preferably the device of the present invention. The bicycle also has a system with a device according to the invention and with an adjustment device for changing at least one suspension parameter of the bicycle’s mechanical suspension as a function of the calculated hardness value. 1

The essence of the invention is that the first or second gradient value is outputted, depending on the magnitude of the quotient of the two gradient values. If the quotient is greater than 1, the first gradient value is outputted as the output value, and if the quotient is less than 1, the second gradient value is outputted as the output value. 5 Alternatively, the first or second gradient value can be outputted, depending on the difference between the two gradient values. Furthermore, the first or second gradient value may be outputted, depending on the first and second gradient values and a plurality of vehicle parameters. The vehicle parameters concerned may be bicycle speed and/or road surface conditions. As another alternative, the first or second gradient value can be io outputted, depending on a weighting function. The weighting function takes into account not only the gradient values but also other quantities such as the bicycle’s speed or items of information as to its mechanical suspension.

The background to the invention is that a gradient value can be ascertained by means of an acceleration sensor — irrespective of the bicycle’s speed and even when the bicycle is is stationary — by measuring the bicycle’s inclination relative to the direction of gravitational acceleration. The background to this possibility of measuring the gradient when the bicycle is stationary is that the acceleration sensor always measures gravitational acceleration as well, and the gravitational-acceleration value is eliminated during further consideration. By means of the direction of a gravitational acceleration vector, it is also possible, using the 2o acceleration sensor, to establish a vertical spatial axis. If the position of the acceleration sensor changes, e.g. due to rotation of the sensor, connected with tilting of the spatial axis (derived from gravitational acceleration) relative to the direction of the gravitational-acceleration vector, then the tilt angle of the sensor can be determined from the change in the measured acceleration. The gradient value outputted can be used for actuating a motor 25 that can be used to run an electric bicycle. The greater the gradient, the greater will be the support provided to the electric bicycle by the motor. Furthermore, the outputted gradient value can be used e.g. to show the energy being expended during riding, on a “Sport Display”. The background to determining energy expenditure during the operation of the bicycle is that, with a steeper gradient, the rider of the bicycle has to exert greater force to 30 propel the bicycle. The greater the force the rider has to apply, the higher his energy expenditure will be.

In an embodiment of the invention, a signal representing a hardness value of a mechanical suspension of a component of the bicycle is outputted as a function of the quotient of the two gradient values. Alternatively, this signal can also be outputted as a function of a difference 35 between the two gradient values. The mechanical suspension concerned can be a front axle suspension, a rear axle suspension, or a saddle suspension. 2

In an embodiment of the invention, at least one parameter of the mechanical suspension is adjusted as a function of the suspension’s hardness value calculated by means of the model. The suspension parameter concerned can be the damping of the mechanical suspension. In particular, an adjustment device is provided, to set the suspension parameter. 5 This adjustment device can be a motor, particularly an electric motor, or a device for altering a fluid’s physical condition, for example its pressure, temperature, or viscosity. The adjustment device is mounted on the bicycle’s front axle suspension and/or rear axle suspension and/or saddle suspension.

In an embodiment of the invention, a pressure sensor is provided on the bicycle’s w handlebars, to detect the at least two pressure quantities.

In an embodiment of the invention, an acceleration sensor is provided in a transmission unit and/or a motor on the bicycle, to detect the at least one acceleration quantity. Such a motor is, in particular, a mid-mounted motor.

Further advantageous forms of embodiment of the invention are the subject matter of the is dependent claims.

Brief Description of the Drawings

Fig. 1 is a schematic representation of a relationship between a first gradient quantity determined by means of an acceleration sensor and a second gradient quantity determined by means of at least two pressure sensors; 20

Fig. 2 is a schematic representation of a bicycle according to the invention;

Fig. 3 is a schematic representation of a device according to the invention; and

Fig. 4 is a schematic representation of a method according to the invention.

Examples of the Invention

The invention will be explained below with reference to forms of embodiment from which 25 further inventive features will emerge. The Figures show some embodiment examples.

Fig. 1 shows schematically the relationship between a sensor signal SG, representing the gradient of a plane under a bicycle as determined from sensor information, and the actual gradientsT of the plane. Plot 101 is the plot of the gradient-quantity as determined with an acceleration sensor. Plot 102 is the plot of the gradient-quantity as determined with at least 3 two pressure sensors. The gradient-quantities are signals representing gradient values. Up to a particular gradient value that depends on the type of acceleration sensor employed, both gradient-quantities essentially coincide with the actual gradient; but from that gradient value onwards, the gradient-quantity according to the acceleration sensor lies above the 5 actual gradient, whereas the gradient-quantity according to the pressure sensor continues to correspond to the actual gradient. The difference between the plots 101 and 102 of the gradient-quantities results primarily from the fact that, when a bicycle goes uphill, its load distribution shifts in the direction of the rear axle. Therefore, when a bicycle is going uphill, a steeper gradient will be determined as a function of the acceleration sensor than as a io function of the pressure sensor. The reason for this is that, due to the increased load applied to the rear axle, a bicycle’s front axle suspension will extend, resulting in tilting of the bicycle relative to the ground beneath it and relative to the direction of gravitational acceleration. Thus, the acceleration sensor measurements show greater gradients when there is an increased load on the rear axle due to riding uphill. The pressure sensor, on the other hand, is only measures the difference between the pressures at two or more places, and this difference is scarcely affected by the tilting of the bicycle. Therefore, the gradient as measured by the pressure sensor corresponds more nearly to the actual gradient. During normal bicycle-riding, the two gradient quantities can be compared with each other. The differences or quotients of the two gradient quantities can be entered in a look-up table. A 2o large difference between the two gradient quantities obtained may indicate either that the bicycle’s suspension is set very soft, because the suspension extends readily, or else that the bicycle has full suspension, with the tilting of the bicycle being further increased by an overly-soft front-axle suspension plus a rear-axle suspension.

The information as to the overly soft mechanical suspension can be provided to the rider or 25 can be used as information for an automatically adjustable mechanical suspension. In the case of an automatically adjustable mechanical suspension, the information can be used to set the mechanical suspension. If the difference between the gradient quantities changes periodically, this may indicate that the bicycle is used by different riders. This information can be stored, and used e.g. for analysis purposes during maintenance. For example, said 30 information enables possible bicycle-wear — related to the rider’s weight — to be determined.

The information about the mechanical suspension, and the analysis of the two gradient-quantities in different riding situations, can also be used to produce a gradient value, which can be used for motor readout or control purposes. Generally, a function is established for 35 this purpose, as follows: 4 d — f(Gbarc>! Clacci Vj ^suspensi P) (1) where a is the outputted gradient, abaro is the gradient as calculated by a barometric pressure sensor, aacc is the gradient as represented by the acceleration sensor, v is the bicycle’s speed, ksuspens is the suspension-stiffness, and p is other bicycle and roadway parameters 5 such as the road surface conditions. In a preferred case, the function may be Q = A Qbaro + B (^acc + C) (2) where A and B are the weighting factors, which add up to a value of 1; and C represents a correction term, which corrects the value from the acceleration sensor, and which is determined according to the previously-established look-up table. If it is found that, over the 10 gradients’ entire range, there are no occurrences of differences between the gradients obtained from the barometric pressure sensor and the acceleration sensor, then the suspension has probably been set hard or is possibly non-existent. Therefore, mainly the acceleration sensor value can be used, during riding, as a gradient reference for setting and readout purposes. Thus, in equation (2), the weighting factors will be A = 0 and B = 1. The is same weighting will also be employed when the bicycle is stationary, v = 0 km/h, since the value abaro is not available.

In another case, in which differences between the acceleration sensor and the barometric pressure sensor occur continually over the entire range, only the pressure sensor value will be used, since it is largely independent of suspension-fork quantities. Here, the weighting 2o factors in equation (2) will be A = 1 and B = 0.

In some cases, either the barometric pressure sensor or the acceleration sensor may output the more reliable signal, depending on the situation. For example, during off-road riding, or strong acceleration, the acceleration sensor will in some circumstances be disturbed, and the signal from the barometric pressure sensor will be more reliable. In other cases, such as 25 on a level roadway or a gentle gradient, the acceleration sensor will usually provide a more reliable signal than the barometric sensor.

Fig. 2 is a schematic representation of the inventive bicycle in a first form of embodiment of the invention. This bicycle F has: a pressure sensor DS; a suspension fork FG; a motor M; a drive unit AE, in which an acceleration sensor BS may be provided; and a device V for 30 producing a gradient value, containing a processing unit VA. This processing unit VA is mounted, for example, on the handlebars of the bicycle F and is suitable for performing the method of the present invention. 5

Fig. 3 is a schematic representation of a device V for generating a gradient value. The device V has a processing unit VA to perform the method of the invention. The processing unit VA acquires sensor-determined signals. The signals can be obtained with a sensor BS and a sensor DS, and transmitted to the processing unit VA. Sensor BS may be an 5 acceleration sensor. Sensor DS may be a pressure sensor. The processing unit VA produces gradient quantities as signals. These gradient quantities represent gradient values. 2015295832 27 Feb 2017

The gradient quantities can be outputted from the processing unit VA and transmitted to a display A, where they are displayed as gradient values. In order to generate control signals, a motor controlling means can be provided inside or outside of the processing unit VA. The io control signals can be transmitted to a motor M. The motor M can be used to run an electric bicycle, particularly when starting off from stationary. Other control signals generated can be transmitted to an adjustment device E; to generate these other signals, an adjustment controlling means can be provided inside or outside of the processing unit VA. The adjustment device E can be used to set a bicycle’s mechanical suspension. The gradient 15 values can also be transmitted to a storage device S and stored there. The gradient values stored in the storage device S can be used for analysis purposes.

Fig. 4 is a schematic representation of a method according to the invention. This procedural method is started automatically. In Acquisition Step 1, at least two pressure quantities and at least one acceleration quantity are acquired. In the next step, Generation Step 2, one 20 gradient value is generated as a function of the at least two pressure quantities, and another gradient value is generated as a function of the at least one acceleration quantity. In the next step, Test Step 3, testing is performed to determine which of the two gradient values is to be outputted. For this, the quotient of the second gradient value to the first gradient value is calculated. Depending on the magnitude of this quotient, the first or second gradient value is 25 outputted or stored, in Output Step 4. Outputting preferably occurs on a display device A of a tachometer. In End Step 5, the procedural method is ended. After End Step 5, the procedural method can be repeated.

In this specification, the terms “comprise”, “comprises”, “comprising” or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common 30 general knowledge. 6 2945950v1

Claims

Claims

1. A method for generating a gradient value, with the following steps: - detecting at least two pressure quantities by means of a pressure sensor, and at least one acceleration quantity by means of an acceleration sensor; and - generating a first gradient value as a function of the at least two pressure quantities, and a second gradient value as a function of the at least one acceleration quantity, and - outputting the first or second gradient value, depending on the magnitude of the quotient of the two gradient values.
2. A method as claimed in claim 1, including the further step of: - outputting a calculated hardness value for a mechanical suspension as a function of the quotient of the two gradient values.
3. A method with the method steps as claimed in claim 2, for actuating an adjustment device, including the further step of: - changing at least one suspension parameter of the mechanical suspension as a function of the calculated hardness value.
4. A device, with a processing unit, for generating a gradient value, said device being particularly suitable for performing a method as claimed in claims 1 to 3, and said processing unit: - acquiring at least two sensor-determined pressure quantities and at least one sensor-determined acceleration quantity, and - generating a first gradient value as a function of the at least two pressure quantities, and a second gradient value as a function of the at least one acceleration quantity, wherein: - the processing unit outputs a signal representing the first or second gradient value, depending on the magnitude of the quotient of the two gradient values.
5. A device as claimed in claim 4 or 5, wherein the processing unit outputs a signal representing a hardness value of a mechanical suspension, as a function of the magnitude of the quotient of the two gradient values.
6. A system with a device as claimed in claim 4 or 5, wherein the system has an adjustment device, and the adjustment device changes at least one suspension parameter of the mechanical suspension as a function of the calculated hardness value.
7. A bicycle, preferably an electric bicycle, containing a device as claimed in claim 4 or 5.
8. A bicycle as claimed in claim 7, with a system as claimed in claim 6.