WO2017155446A1

WO2017155446A1 - Measuring Device for Assessing a Torque Parameter of a Vehicle and Method for Assessing a Torque Parameter of a Vehicle

Info

Publication number: WO2017155446A1
Application number: PCT/SE2017/050191
Authority: WO
Inventors: Patrik RÖNNQVIST; Bo Warmenius
Original assignee: Scania Cv Ab
Priority date: 2016-03-08
Filing date: 2017-03-01
Publication date: 2017-09-14
Also published as: SE1650310A1; DE112017000605T5; SE540356C2

Abstract

Herein a measuring device (2) for assessing a torque parameter of a vehicle comprising a first yoke (4), a second yoke (6), a universal joint cross (8), and an axle (10) having a first end portion (12) and a second end portion (14). A torsion sensor (18) is attached to the first end portion (12). Further, herein a method for assessing a torque parameter of a vehicle is disclosed.

Description

Measuring Device for Assessing a Torque Parameter of a Vehicle and Method for Assessing a Torque Parameter of a Vehicle

TECHNICAL FIELD

The present invention relates to a measuring device for assessing a torque parameter of a vehicle and a method for assessing a torque parameter of a vehicle. The present invention further relates to a computer program and to a computer program product.

BACKGROUND

A torque of a drive unit, such as an internal combustion engine and/or a transmission, transmitted to at least one drive wheel of a vehicle may be assessed in different ways and for various purposes. The torque may be assessed via the amount of fuel injected into an internal combustion engine of the drive unit, via calculation based on vehicle weight and vehicle acceleration, or measured utilising various sensors. The torque may be e.g.

assessed for controlling gear shifting in the transmission, for controlling vehicle speed, or for verifying torque performance of the drive unit or other parts of a powertrain of the vehicle.

GB 1309892 discloses torque transducers. The torque transmitted by a shaft is measured by resistance strain gauges located on a reduced diameter portion of the shaft, which is covered by a stiff sleeve member. The signal from the strain gauges is taken out by slip rings secured to the sleeve.

GB 918338 discloses a torque transducer of the type having strain gauges mounted to measure the twist of a shaft transmitting the torque. A slip ring assembly is detachably mounted over the portion of the shaft to which the strain gauges are attached. A shaft has a portion of reduced diameter to which the resistance strain gauges are attached. The connections to the strain gauges are taken via a channel in the shaft to a plug in a flange attached to the shaft. The slip ring assembly comprises a sleeve having a flange carrying a socket to mate with a plug. The flange being secured to a flange of the shaft, by screws. The sleeve carries a plurality of ring electrodes which dip into pools of mercury carried in chambers formed in the block which is rotatably mounted on the sleeve by means of bearings. The plug is connected to metallic parts of the mercury chambers to establish electrical contact, via the mercury, with the electrodes which are in turn connected via plug and socket with the strain gauges. WO 0208048 discloses a rotatable assembly for a vehicle road wheel and includes a vehicle suspension knuckle, a drive shaft, a first bearing carried by the knuckle for rotatably supporting the drive shaft, a wheel hub drivingly connected to the drive shaft, a brake disc support rotatably carried by the first bearing and connected to the drive shaft to rotate therewith. The connection between the brake disc support and the drive shaft being separated and spaced apart along the shaft from the connection between the drive shaft and the wheel hub. A second bearing between the wheel hub and the brake disc supports the wheel hub and allows relative rotation between the brake disc support and the wheel hub and a torque sensor. The torque sensor is arranged between said connections to sense the torque or the change in torque being transmitted by the drive shaft to the wheel. The measured torque signals may be used as a primary source of information for ABS and/or traction control but could also be used to control automatic gear boxes for smooth gear shifts. US2010200325 discloses a drive shaft assembly with a toque sensor. The driveshaft assembly includes a first shaft member, a second shaft member, a bearing assembly and a sensor. The first shaft member has a magnetically encoded zone with a magnetic field that varies as a function of the torque that is transmitted through the first shaft member. The second shaft member is coupled for rotation with the first shaft member. The bearing assembly comprises a bearing support, which is configured to be coupled to a vehicle structure, and a bearing that is housed in the bearing support. The bearing supports the first shaft member for rotation about a first axis. The sensor is coupled to the bearing assembly. The sensor is arranged to sense the magnetic field of the magnetically encoded zone and responsively produce an electrical signal.

Indirectly assessing the torque of a drive unit may be sufficient in many situations, i.e.

estimating or calculating a torque using related parameters such as amount of fuel injected, or vehicle weight and vehicle acceleration. However, under some circumstances such indirect methods are not precise enough, and at least one torque parameter of a drive train of a vehicle has to be measured, e.g. for diagnosing vehicle behaviour, or for calibrating one or more vehicle functions.

SUMMARY

It is an object of the present invention to provide a measuring device for assessing a torque parameter of a vehicle, which may be utilised for occasional precise torque assessment in a vehicle. According to an aspect of the invention, the object is achieved by a measuring device for assessing a torque parameter for a vehicle comprising a first yoke, a second yoke, a universal joint cross, and an axle having a first end portion and a second end portion. The first and second yokes are connected to each other via the universal joint cross. The first yoke is connected to the first end portion of the axle. The second end portion of the axle is provided with splines. The second yoke is configured for connection to a powertrain of a vehicle. The second end portion of the axle forms part of a slip joint. The measuring device for assessing a torque parameter for a vehicle comprises a torsion sensor attached at the first end portion.

Since the measuring device for assessing a torque parameter for a vehicle is designed in the form of a universal joint and comprises splines arranged at the second end portion of the axle, the measuring device is configured to replace an ordinary universal joint arrangement in a powertrain of a vehicle for the purpose of assessing a torque parameter in the vehicle. Moreover, since the measuring device comprises a torsion sensor, precise torque measurements in the vehicle powertrain may be provided. As a result, the above mentioned object is achieved.

In particular, as the second end portion comprising splines forms part of a slip joint, the measuring device for assessing a torque parameter of a vehicle may be connected with a propeller shaft of the powertrain, wherein an end portion of the propeller shaft forms a mating part of the slip joint. Thus, the ordinary universal joint arrangement may be easily demounted from the vehicle by detaching a second yoke of the universal joint arrangement from the powertrain and simply sliding apart a slip joint with the propeller shaft in order to thereafter slide the splines of the measuring device onto the propeller shaft and attach the second yoke of the measuring device to the powertrain.

One advantage with designing the measuring device for assessing a torque parameter of a vehicle as a universal joint arrangement is that universal joint arrangements are largely harmonised design elements of vehicles. Thus, one vehicle manufacturer may use the same type of universal joint arrangement in a number of different vehicle models, whereas other parts of the powertrain have to be manufactures vehicle model specific. Accordingly, if a measuring device for assessing torque in a powertrain of a vehicle instead were to be designed as a propeller shaft, a much larger variety of the such measuring devices would have to be provided in order to be able to provide corresponding torque measurements from the different vehicle models of the relevant manufacturer. The measuring device for assessing a torque parameter of a vehicle may be utilised in various kinds of motorised manned or unmanned vehicles, designed for land-based propulsion. However, in particular for heavy goods vehicles such as lorries, trucks, pickups, vans, wheel loaders, busses, and other heavy vehicles, assessment of a vehicle torque parameter may be of particular relevance. Thus, it is particularly foreseen to use the measuring device for assessing a torque parameter of a vehicle in heavy goods vehicles.

According to some embodiments the measuring device for assessing a torque parameter of a vehicle comprises a sleeve connected to the first yoke and extending in parallel with at least a portion of the axle at a radial distance from the axle, wherein the sleeve extends over the torsion sensor. In this manner the torsion sensor may be protected by the sleeve from stone chipping and other external damage.

According to some embodiments, the torsion sensor comprises a strain gauge. In this manner a torque transferred via the measuring device may be easily measured. The strain gauge provides a reading, which is directly proportional to transferred torque. Thus, after calibrating the measuring device, readings from the strain gauge may provide measurements of the torque transferred via the measuring device. It is further object of the present invention to provide a method for assessing a torque parameter of a vehicle, which may be utilised in occasional precise torque assessment in a vehicle.

According to a further aspect of the invention, the above mentioned object is achieved by a method for assessing a torque parameter of a vehicle. The vehicle comprising at least one drive wheel and a powertrain for driving the at least one drive wheel. The powertrain comprises a drive unit, a universal joint arrangement, and a propeller shaft. The universal joint arrangement is connected to the propeller shaft via a slip joint. The method comprises steps of:

- demounting the universal joint arrangement from the powertrain,

- replacing the universal joint arrangement with a measuring device for assessing a torque parameter of a vehicle comprising a torsion sensor according to any aspect and/or embodiment discussed herein,

- rotating the propeller shaft with the drive unit,

- reading a measurement value from the torsion sensor,

- determining the torque parameter based at least partially on the measurement value from the torsion sensor. Since the method provides for replacement of a universal joint arrangement with a measuring device for assessing a torque parameter of a vehicle according to aspects and/or

embodiments discussed herein, and determining the torque parameter of the vehicle based at least partially on the measurement value from the torsion sensor of the measuring device, the above mentioned object is achieved.

Moreover, assessing a torque parameter under operation of the relevant vehicle during realistic operating conditions, i.e. in traffic and on roads with load, is made possible by the present method. Thus, the less than realistic operating conditions in a vehicle dynamometer may not be required for assessing a torque parameter.

The torque parameter may be a torque figure, but also figures calculated based on a torque figure, such as e.g. a power figure, is herein encompassed by the term torque parameter. The torque parameter may be e.g. a momentary torque value, a mean torque value, a momentary power value, or a mean power value.

According to a further aspect of the invention there is provided a computer program for performing a method for assessing a torque parameter of a vehicle, wherein the computer program comprises computer readable code configured to cause a central processing unit to perform a method according to any aspect and/or embodiment discussed herein.

According to a further aspect of the invention there is provided a computer program product for performing a method for assessing a torque parameter of a vehicle, wherein the computer program comprises computer readable code configured to cause a central processing unit to perform a method according to any aspect and/or embodiment discussed herein.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which:

Figs. 1 A and 1 B illustrate a measuring device for assessing a torque parameter of a vehicle according to embodiments,

Fig. 2A schematically illustrates a vehicle comprising a powertrain, Fig. 2B illustrates a measuring device for assessing a torque parameter of a vehicle and a propeller shaft,

Fig. 3 illustrates a method for assessing a torque parameter of a vehicle,

Fig. 4 illustrates a computer program product according to embodiments.

DETAILED DESCRIPTION

Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Figs. 1 A and 1 B illustrate a measuring device 2 for assessing a torque parameter of a vehicle according to embodiments. Fig. 1 A illustrates a partial cross section through the measuring device 2 for assessing a torque parameter of a vehicle. The measuring device 2 is configured for use in a powertrain of a vehicle. More specifically, the measuring device 2 is designed as a universal joint arrangement. As such the measuring device 2 is configured to replace an ordinary universal joint arrangement of a powertrain of a vehicle. Thus, the measuring device 2 may be utilised for occasional precise torque assessment in the powertrain of a vehicle. The measuring device 2 for assessing a torque parameter of a vehicle comprises a first yoke 4, a second yoke 6, and a universal joint cross 8. The first yoke 2 is connected to the universal joint cross 8 and the second yoke 6 is also connected to the universal point cross 8. Thus, the first and second yokes 4, 6 are connected to each other via the universal joint cross 8. The first and second yokes 4, 6 comprise bearing seats for the universal joint cross 8, which accordingly, is journalled in the first and second yokes 4, 6 to form a universal joint. The measuring device 2 further comprises an axle 10 having a first end portion 12 and a second end portion 14. The first yoke 4 is connected to the first end portion 12 of the axle 10. The first yoke 4 being connected to the first end portion 12 of the axle 10 encompasses embodiments wherein the first yoke 4 and the axle 10 are formed from one piece, as well as embodiments wherein the first yoke 4 is attached to the axle 10. The axle 10 may be hollow as in the illustrated embodiments. Alternatively, the axle 10 may be solid. The second end portion 14 of the axle 10 is provided with splines 15 thus, forming part of a slip joint. The slip joint being formed together with a corresponding mating part of a powertrain of a vehicle, e.g. a propeller shaft.

Also the second yoke 6 is configured for connection to the powertrain. The second yoke may for instance be connected to the powertrain via screws, threaded bolts and nuts, pins and clips, or any other mechanical fastening arrangement which permits dismantling of the second yoke from the drive of a vehicle. In these embodiments of the second yoke 6 is provided with a four through holes 16 for connection to the powertrain. For instance, screws or pins may extend through the four through holes 16 such that the second yoke 6 may be tightened e.g. to an output end of a transmission of a drive unit of the vehicle. Alternatively, the second yoke 6 may be tightened to an end gear and/or a differential connected to at least one drive wheel of the powertrain.

The measuring device 2 for assessing a torque parameter of a vehicle comprises a torsion sensor 18 arranged at the first end portion 12. In these embodiments the torsion sensor 18 comprise a strain gauge. The strain gauge is glued to the first end portion 12 of the axle at 10. According to some embodiments, the strain gauge may comprise electrical conductors arranged at a 45° angle to a longitudinal axis 20 of the axle 10. In this manner the electrical conductors of the strain gauge extend are arranged on the axle 10, such that torsional forces, i.e. torque, applied to the axle 10 extend or compress the electrical conductors efficiently. For instance, a general purpose strain gauge having a shear/torque pattern provided by Micro - Measurements™, Vishay Precision Group™ may be utilised. The electrical conductors of the strain gauge may form a Wheatstone bridge or half a Wheatstone bridge.

A torsion sensor measures a torsion of the axle 10. A torsion of an axle is proportional to a torque applied to the axle. According to alternative embodiments, the torsion sensor 18 may be of any suitable kind. For instance, the torsion sensor 18 may comprise a magnetically encoded zone with a magnetic field that varies as a function of the torque that is transmitted through the axle 10, as discussed under the heading "Background" above. Further options may be to utilise optical torsion sensors, or piezo-electrical sensors, as are known in the art.

The measuring device 2 for assessing a torque parameter of a vehicle comprises a sleeve 22 connected to the first yoke 4. The sleeve 22 extends in parallel with at least a portion of the axle 10 at a radial distance from the axle 10. The sleeve 22 extends over the torsion sensor 18. In this manner the torsion sensor may be protected from stone chipping and other external damage by the sleeve.

According to some embodiments the measuring device 2 for assessing a torque parameter of a vehicle comprises a wireless transmitter 24. The torsion sensor 18 is connected to the wireless transmitter 24. In this manner measurement values from the torsion sensor 18, or database on the measurement values, or the measurement values together with additional data may be transmitted to a receiver. Thus, the measuring values may be utilised in further calculations and/or may be presented for evaluation.

According to alternative embodiments, measurement values from the torsion sensor 18 may be conducted to a receiver via slip rings arranged on e.g. the sleeve 22.

According to some embodiments, the wireless transmitter 24 is attached to the sleeve 22. Wires (not shown) may connect the torsion sensor 18 with the wireless transmitter 24. The wireless transmitter 24 may comprise a processor for aggregation of measurement values from the torsion sensor 18, and/or other data. The transmitter 24 may for instance comprise a Wireless 2 Channel Analog Input Sensor Node provided by LORD MicroStrain ® Sensing Systems.

According to some embodiments, the measuring device 2 for assessing a torque parameter of a vehicle comprises a controller 26 configured to sample measurement values from the torsion sensor 18. In this manner the measuring device 2 may be configured to sample measurement values for continuous torque measurement with the measuring device 2 for assessing a torque parameter of a vehicle. The controller 26 may form one physical unit together with the wireless transmitter 24. Alternatively, the controller 26 may comprise a receiver 25 and may be provided separate from the wireless transmitter 24, such as in an all- purpose computer, a dedicated processing device of the measuring device such as e.g. a gateway of a LORD MicroStrain ® LXRS ® Wireless Sensor Network, or other suitable device. The controller 26 may be configured for processing, and/or evaluation, and/or presentation of measurement values and/or data based on measurement values.

Alternatively, the controller 26 may only provide partial processing of the measurement values, and/or sampling of the measurement values and send these to a device for evaluation, and/or presentation of the measurement values, and/or torque parameters based on the measurement values, such as she a general purpose computer with a general software for data presentation or to a dedicated software for evaluation, calculation, and/or presentation of torque parameters, such as the programme Node Commander ® provided by LORD MicroStrain ® Sensing Systems.

The wireless transmitter 24 may transmit for each measurement value a timestamp to the controller 26. Alternatively, the controller 26 may provide for each measurement value a timestamp. The timestamp may be utilised for presenting the measurement values, or torque values based on the measurement values, in a correct order, such as e.g. in a diagram or in a table. The timestamp may be utilised for correlating the measurement values, or torque values based on the measurement values with further data, such as e.g. rotational speed data of a drive unit of a relevant vehicle. The timestamp may be utilised for calculating further data, such as developed power in a drive unit of the vehicle. According to some embodiments, the splines 15 comprise ridges and grooves and the second end portion 14 has a bottom diameter, d2, at a bottom of the grooves. The first end portion 12, at the torsion sensor 18, has a smaller diameter, d1 , than the bottom diameter, d2. In this manner, the torsion sensor 18 may be arranged on the first end portion 12 not extending outside the bottom diameter, d2. Thus, a mating part of the slip joint of a relevant propeller shaft may extend along the first end portion 12 without harming the torsion sensor 18.

Mentioned purely as an example, for a heavy goods vehicle having a diesel engine producing a torque within a range of 1500 - 3500 Nm, the measuring device may have a bottom diameter, d2, of approximately 65 mm, the diameter, d1 , at the torsion sensor may be approximately 60 mm, and the axle 10 extending from the first yoke 4 may have a length of approximately 270 mm. The universal joint cross 8 may have a span of approximately 175 mm and a journaling diameter of approximately 55 mm. The sleeve may have a length of approximately 160 mm and a diameter of approximately 120 mm.

The measuring device 2 for assessing a torque parameter of a vehicle may be calibrated prior to being installed in a relevant vehicle. The measuring device 2 may be calibrated by fixing the second yoke 6 and subjecting the axle 10 to a number of known torque values. For each of the number of known torque values a reading from the torsion sensor 18 is taken. Accordingly, the readings from the torsion sensor 18 may be correlated with the known torque values. Since the torsion, twisting, of the axle 10 is proportional to the torque applied to the measuring device 2, torque values in between the known torque values may be interpolated. Thus, during use of the measuring device 2, measurement values from the torsion sensor 18 may be correlated with the torque values transferred via the measuring device 2.

A measuring device comprising a torsion sensor comprising a strain gauge may alternatively be calibrated in a known manner by means of shunt calibration utilising inter alia a shunt resistor and a gauge factor of the relevant strain gauge provided by a manufacturer of the strain gauge. In embodiments wherein the torsion sensor 18 comprises a strain gauge, a voltage applied to the strain gauge will change proportionately to the torque applied to the measuring device 2.

Fig. 2A schematically illustrates a vehicle 30 comprising a powertrain 32. The powertrain 32 comprises a measuring device 2 for assessing a torque parameter of a vehicle according to aspects and/or embodiments disclosed herein.

The vehicle comprising at least one drive wheel 34, more specifically in these embodiments, two drive wheels 34. The powertrain 32 is configured for driving the at least one drive wheel 34. The powertrain comprises a drive unit 36, the measuring device 2 for assessing a torque parameter of a vehicle, and a propeller shaft 38. The measuring device 2 for assessing a torque parameter of a vehicle is provided in the form of a universal joint arrangement. During ordinary operation of the vehicle 30 an ordinary universal joint arrangement is comprised in the powertrain 32. For measuring purposes, e.g. in order to measure a torque provided by the drive unit 36, the ordinary universal joint arrangement has been replaced with the measuring device 2 for assessing a torque parameter of a vehicle.

Fig. 2B illustrates the measuring device 2 for assessing a torque parameter of a vehicle and the propeller shaft 38 of Fig. 2A in more detail. The measuring device 2 and the propeller shaft 38 are illustrated in a partial cross section. The measuring device 2 is connected to the propeller shaft 38 via a slip joint 40. The slip joint 40 comprises external splines 15 on the measuring device 2, as discussed above with reference to Figs. 1 A and 1 B, and mating internal splines 39on the propeller shaft 38. Returning to Fig. 2A, the drive unit 36 comprises a combustion engine 42 a clutch 44 and a transmission 46. The measuring device 2 is connected to an output shaft of the transmission 46, as discussed above with reference to Figs. 1 A and 1 B. The powertrain 32 may further comprise and end gear 48 and two drive shafts 50. The end gear 48 may comprise a differential. The propeller shaft 38 may be connected to the end gear 48 via a universal joint 52. The end gear 48 is connected to the two drive shafts 50, each being connected to a drive wheel 34.

Mentioned purely as an example, in an implementation of the embodiments of Figs 2A and 2B, wherein the measuring device 2 is connected to the transmission 46 by means of four screws extending through four through holes of a second yoke of the measuring device 2, replacing the ordinary universal joint arrangement with the measuring device 2 may be performed in less than 10 minutes on a long-haulage tuck, without lifting the truck. The replacement includes demounting the ordinary universal joint arrangement from the transmission, lowering the propeller shaft together with the ordinary universal joint arrangement, sliding the ordinary universal joint arrangement from the propeller shaft, sliding the measuring device onto the propeller shaft, and mounting the measuring device to the transmission.

The embodiments of Figs 2A and 2B illustrate one possible position of the measuring device 2 in the powertrain 32. Alternative positions for the measuring device 2 may be at the end gear end of the propeller shaft 38, or at a support bearing between the transmission 46 and the propeller shaft 38, or at a transfer gearbox, just to name a few. In alternative

embodiments, the drive unit 36 may comprise an electric machine.

The combustion engine 42 may comprise the rotational speed sensor 54 for measuring a rotational speed of the combustion engine 42 in a known manner. The rotational speed sensor 54 may for instance form part of an engine control system of the vehicle. Data from the rotational speed sensor 54 may be available via a diagnosis program. The rotational speed data may be utilised in calculation of a vehicle data together with the measurement values, or torque values based on the measurement values from the torsion sensor of the measuring device 2 for assessing a torque parameter of a vehicle. The rotational speed data may be timestamped in order to be correlated with the relevant measurement values from the torsion sensor, or for calculating torque parameters based on the measurement values and the rotational speed data.

Fig. 3 illustrates a method 100 for assessing a torque parameter of a vehicle. The vehicle may be a vehicle 30 as discussed in connection with Figs 2A and 2B and comprises at least one drive wheel and a powertrain for driving the at least one drive wheel. The powertrain comprises a drive unit, a universal joint arrangement, and a propeller shaft. The universal joint arrangement is connected to the propeller shaft via a slip joint. The method 100 comprises steps of:

- demounting 102 the universal joint arrangement from the powertrain,

- replacing 104 the universal joint arrangement with a measuring device comprising a torsion sensor according to any aspect and/or embodiment discussed herein,

- rotating 106 the propeller shaft with the drive unit,

- reading 108 a measurement value from the torsion sensor,

- determining 1 10 the torque parameter based at least partially on the measurement value from the torsion sensor. The measuring device has replaced the original universal joint arrangement of the vehicle. A torque parameter related to the vehicle and affecting the torsion sensor thus, may be easily measured. The step of determining 1 10 the torque parameter may be performed in a central processing unit, a processor, controller, or similar device. The measurement value from the measuring device is transferred to the central processing, processor, controller, or similar device. Based on the measurement value, the central processing, processor, controller, or similar device may determine the torque parameter e.g. by comparing the measurement value with a look- up table to determine the torque parameter, or calculate the toque parameter using at least on relevant formula and possibly a further input value or input values, such as a rotational speed of the measuring device or the drive unit, or correlating the measurement value with a relevant value of the torque parameter. According to some embodiments, the method 100 for assessing a torque parameter of a vehicle comprises steps of:

- measuring 1 12 a rotational speed value of the drive unit or the propeller shaft

simultaneously with the step of reading 108 the measurement value from the torsion sensor, and wherein the step of determining 1 10 the torque parameter comprises a step of:

- correlating 1 14 the torque parameter with the rotational speed value.

In this manner for a specific rotational speed a specific value of the torque parameter may be correlated. This may for instance be utilised when presenting the torque parameter and rotational speed value to a user, or when calculating the torque parameter when the torque parameter comprises the rotational speed, such as e.g. in a power value.

According to some embodiments, the method 100 for assessing a torque parameter of a vehicle comprises steps of:

- repeating 1 16 the steps of: reading 108 a measurement value from the torsion sensor, measuring 1 12 a rotational speed value of the drive unit or the propeller shaft simultaneously with the measurement value from the torsion sensor, and determining 1 10 the torque parameter,

- correlating 1 18 at least some of the torque parameters thus determined with at least some of the rotational speed values, and

- mapping 120 the torque parameters with their correlated rotational speed values. In this manner the torque parameters, e.g. torque values may be mapped against corresponding rotational speed values. The mapping 120 may for instance be presented graphically in a torque - rpm diagram, a torque - rpm table, a power - rpm diagram, or power

- rpm diagram, on a display or a printed paper.

- transmitting 122 wirelessly the measurement value or a determined torque parameter from the torsion sensor to a receiver, and

- logging 124 the measurement value from the torsion sensor or a determined torque parameter, in a memory.

In this manner the measurement value from the torsion sensor or the determined torque parameter may be transferred to a computer memory. The measurement value or the determined torque parameter then is available for further processing thereof, such as the above mentioned steps of determining 1 10, correlating 1 14, correlating 1 18, and/or mapping 120.

According to some embodiments, the measurement value corresponds to a torque value transmitted from the drive unit via the measuring device to the at least one drive wheel.

The measurement value from the torsion sensor may directly correlate with a torque value as discussed above. Utilising relevant gear ratios, transmission losses, etc., a torque value of the drive unit, specifically a combustion engine thereof, may be assessed. Furthermore, a power value of the internal combustion engine may be calculated based on the torque value, T, and a rotational speed value, o, of the combustion engine, wherein the power, P = T ^* o. For instance, in this context the timestamp of the measurement value and the rotational speed value may be utilised. Alternatively, measurement values from the torsion sensor and the rotational speed sensor of the combustion engine may be sampled simultaneously to ensure correlation therebetween.

According to some embodiments, the method 100 for assessing a torque parameter of a vehicle comprises a step of:

- calculating 126 a drive unit torque value based on the torque parameter.

Such a drive unit torque value may for instance be an output torque of a combustion engine of the drive unit. Mentioned purely as an example, during performing the method 100 for assessing a torque parameter of a vehicle, the relevant vehicle may be loaded close to its maximum loading capacity and driven along a steep uphill road section. Suitably, the vehicle speed may be high at a beginning of the road section, but as the vehicle travels along the road section, the vehicle speed will gradually drop. During such operating conditions a full torque range, and power range, of the drive unit of the vehicle may be evaluated.

Fig. 4 illustrates a computer program product 200 according to embodiments. The computer program product 200 is configured for performing a method for assessing a torque parameter of a vehicle, wherein the computer program comprises computer readable code configured to cause a central processing unit to perform a method according to any aspect and/or embodiment discussed herein.

In these embodiments the computer program product 200 comprises a CD-ROM disc.

According to alternative embodiments the computer program product may comprise a different computer readable storage medium, such as a ROM, an EPROM, a CD ROM disc, a USB flash memory, etc.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended claims. For instance, more than one torque sensor may be arranged in the measuring device. Such redundancy of sensors may provide a higher measuring accuracy than if only one torque sensor is used. According to some embodiments the measuring device 2 for assessing a torque parameter of a vehicle may be permanently mounted in a vehicle. Thus, measurement values from the measuring device 2 for assessing a torque parameter of a vehicle may be utilised in vehicle control during ordinary operation of the vehicle, such as e.g. in an engine control system, during gear change in an automated manual transmission, in a brake system, etc.

Claims

1 . A measuring device (2) for assessing a torque parameter of a vehicle comprising a first yoke (4), a second yoke (6), a universal joint cross (8), and an axle (10) having a first end portion (12) and a second end portion (14), wherein

the first and second yokes (4, 6) are connected to each other via the universal joint cross (8), wherein

the first yoke (4) is connected to the first end portion (12) of the axle (10), wherein

the second end portion (14) of the axle (10) is provided with splines (15), wherein

the second yoke (6) is configured for connection to a powertrain (32) of a vehicle (30), and wherein

the second end potion of the axle (10) forms part of a slip joint (40), characterised in that

the measuring device (2) for assessing a torque parameter of a vehicle comprises a torsion sensor (18) attached to the first end portion (12).

2. The measuring device (2) for assessing a torque parameter of a vehicle according to claim 1 , comprising a sleeve (22) connected to the first yoke (4) and extending in parallel with at least a portion of the axle (10) at a radial distance from the axle (10), wherein the sleeve (22) extends over the torsion sensor (18).

3. The measuring device (2) for assessing a torque parameter of a vehicle according to claim 1 or 2, comprising a wireless transmitter (24), wherein the torsion sensor (18) is connected to the wireless transmitter (24).

4. The measuring device (2) for assessing a torque parameter of a vehicle according to claims 2 and 3, wherein the wireless transmitter (24) is attached to the sleeve (22).

5. The measuring device (2) for assessing a torque parameter of a vehicle according to any one of the preceding claims, wherein the splines (15) comprise ridges and grooves and the second end portion (14) has a bottom diameter (d2) at a bottom of the grooves, and wherein the first end portion (12), at the torsion sensor (18), has a smaller diameter (d1 ) than the bottom diameter (d2).

6. The measuring device (2) for assessing a torque parameter of a vehicle according to any one of the preceding claims, comprising a controller (26) configured to sample measurement values from the torsion sensor (18).

7. The measuring device (2) for assessing a torque parameter of a vehicle according to any one of the preceding claims, wherein the torsion sensor (18) comprises a strain gauge.

8. A method (100) for assessing a torque parameter of a vehicle (30), the vehicle (30) comprising

at least one drive wheel (34) and a powertrain (32) for driving the at least one drive wheel (34), the powertrain (32) comprising a drive unit (36), a universal joint

arrangement, and a propeller shaft (38), wherein

the universal joint arrangement is connected to the propeller shaft (38) via a slip joint (40), and wherein

the method (100) comprises steps of:

- demounting (102) the universal joint arrangement from the powertrain (32),

- replacing (104) the universal joint arrangement with a measuring device (2) for assessing a torque parameter of a vehicle comprising a torsion sensor (18) according to any one of the preceding claims,

- rotating (106) the propeller shaft (38) with the drive unit (36),

- reading (108) a measurement value from the torsion sensor (18), and

- determining (1 10) the torque parameter based at least partially on the measurement value from the torsion sensor (18).

9. The method (100) for assessing a torque parameter of a vehicle (30) according to claim 8, comprising steps of:

- measuring (1 12) a rotational speed value of the drive unit (36) or the propeller shaft (38) simultaneously with the step of reading (108) the measurement value from the torsion sensor (18), and wherein the step of determining (1 10) the torque parameter comprises a step of:

- correlating (1 14) the torque parameter with the rotational speed value.

10. The method (100) for assessing a torque parameter of a vehicle (30) according to claims

9, comprising steps of:

- repeating (1 16) the steps of reading (108) a measurement value from the torsion sensor (18), measuring (1 12) a rotational speed value of the drive unit (36) or the propeller shaft (38) simultaneously with the measurement value from the torsion sensor (18), and determining (1 10) the torque parameter,

- correlating (1 18) at least some of the torque parameters thus determined with at least some of the rotational speed values, and

- mapping (120) the torque parameters with their correlated rotational speed values.

1 1 . The method (100) for assessing a torque parameter of a vehicle (30) according to any one of claims 8 - 10, comprising steps of:

- transmitting wirelessly (122) the measurement value or a determined torque parameter from the torsion sensor (18) to a receiver, and

- logging (124) the measurement value from the torsion sensor (18) or a determined torque parameter, in a memory.

12. The method (100) for assessing a torque parameter of a vehicle (30) according to any one of claim 8 - 1 1 , wherein the measurement value corresponds to a torque value transmitted from the drive unit via the measuring device (2) for assessing a torque parameter of a vehicle to the at least one drive wheel (38).

13. The method (100) for assessing a torque parameter of a vehicle (30) according to any one of claims 8 - 12, comprising a step of:

- calculating (126) a drive unit torque value based on the torque parameter.

14. A computer program for performing a method (100) for assessing a torque parameter of a vehicle (30), wherein the computer program comprises computer readable code configured to cause a central processing unit to perform a method (100) according to any one of claims 8 - 13.

15. A computer program product for performing a method (100) for assessing a torque parameter of a vehicle (30), wherein the computer program comprises computer readable code configured to cause a central processing unit to perform a method (100) according to any one of claims 8 - 13.