Dynamic vehicle attitude measurement device

Abstract

An apparatus (100) for dynamic measurement of a vehicle setup having two, three, four or more wheels is provided. The apparatus (100) is adapted to be attached to a wheel (1) of the vehicle and includes one or more non-contact detection sensors (4) for measuring the setup relative to a plane defined by the ground (S). The one or more sensors (4) define at least three mutually incoherent detection axes to determine a plane that intersects the wheel (1) laterally and is integral with the plane (T) and a longitudinal plane (L) passing through the centerline of the wheel (1).

Description

[Technical Field]

[0001] The present invention relates to an apparatus and system for measuring the set-up of a vehicle, in particular for measuring the alignment and orientation parameters of the wheels and suspension with respect to three Cartesian axes and the height of the wheels relative to the ground under load conditions. [Background technology]

[0002] Devices and systems for measuring the set-up of a vehicle are well known in the state of the art.

[0003] Among other things, devices are known for measuring the orientation of the so-called "central plane" of a vehicle wheel relative to the three Cartesian axes, i.e. for measuring these alignment parameters defined by the wheels and suspension of a vehicle, which have a direct influence on driving quality, safety, performance, consumption and wear of mechanical parts, giving the latter a specific setup and a specific attitude in driving behavior.

[0004] In particular, among the most relevant measurement parameters are the camber angle, i.e. the angle between the vertical axis of the wheel and the vertical axis of the vehicle, the caster, i.e. the angular displacement of the steering axis from the vertical axis, and the toe, i.e. the angle of the wheel relative to the longitudinal axis of the vehicle. A further fundamental parameter is represented by the so-called wheel load radius, i.e. the distance between the wheel hub and the ground under vehicle load conditions. Measurement of further parameters and physical quantities is also conceivable.

[0005] Here, the measurements of the above parameters are generally carried out under completely static conditions: in known measurement methods, the vehicle is placed on a special platform in a specialized mechanical workshop, and the above measurements are carried out by devices and detectors that can be installed on the wheels, suspension and body, such as laser range finders, gyroscopes, optical sensors and transducers, and then analyzed and processed by software.

[0006] Patent Document 1 describes a system for detecting the alignment of vehicle wheels, including toe, camber, and caster angles, and the system includes a measuring device with a wireless transmitter, a portable remote device with a wireless receiver, a controller for signal processing, and a display screen. The measuring device includes a camera and / or tilt sensor attached to the wheel on each side of the vehicle.

[0007] These devices have obvious limitations and drawbacks related to the measurement conditions themselves: static type measurements, i.e. measurements with the vehicle stationary and fixed to the ground, do not allow the analysis of the actual wheel and suspension set-up that occurs during the vehicle's movement: acceleration, braking, steering speeds, stresses, etc., strongly influence the distribution of weight, forces and the position of the vehicle's center of gravity, affecting the very geometry of the wheels, suspension and tires, the alignment of mechanical parts and material deformations.

[0008] In static conditions, these behaviors can only be simulated with inaccurate and unreliable calculation and integration methods.

[0009] Patent document 2 discloses a system for measuring the suspension kinematics of a vehicle under dynamic conditions. The system includes devices for measuring the suspension, tire tilt and wheel angle. The measurements are performed via gyroscopic devices connected to each other and associated with a data acquisition and processing device.

[0010] However, these measurements, which are based on gravitational analysis and are performed with reference to a plane defined by the body or chassis of the vehicle, rather than a plane defined by the ground, are subject to inaccurate and inconsistent values.

[0011] Furthermore, devices and methods for measuring the distance of a vehicle's wheels from the ground or systems for measuring camber angles in dynamic conditions are known, such as those described in US Pat. No. 5,623,999. These devices generally use laser distance meters connected to data acquisition and processing devices.

[0012] However, these devices are unable to provide contextual and dynamic conditions for all items useful for defining the vehicle setup as described above. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 1,146,698 [Patent Document 2] Chinese Patent Application Publication No. 103852268 [Patent Document 3] Chinese Patent Application Publication No. 110044270 Summary of the Invention [Problem to be solved by the invention]

[0014] It is therefore an object of the present invention to provide an apparatus that overcomes and avoids the main deficiencies and most serious limitations of the prior art.

[0015] In particular, a device is provided that is adapted to measure key parameters that define the set-up of a vehicle in dynamic conditions, for example during road or track testing.

[0016] These measurements are made directly on the road surface in a non-contact mode by sensors integrated into the wheel surface, offering clear advantages in terms of usability and advancement over the prior art, accuracy and consistency of measurements, and above all, the present invention does not require the use of complex and inaccurate calculations and simulation algorithms. [Means for solving the problem]

[0017] These and other objects are achieved by the device set forth in the claims.

[0018] According to the present invention, there is provided an apparatus for dynamic measurement of the set-up of a vehicle having two, three, four or more wheels, the apparatus being adapted to be mounted on a wheel of said vehicle and comprising one or more non-contact detection sensors for measuring said set-up relative to a plane defined by the ground.

[0019] In particular, the one or more sensors define at least three detection axes aligned with each other to determine a plane that laterally intersects the wheel, the one or more sensors being integral with the plane and a longitudinal plane passing through the centerline of the wheel.

[0020] According to a preferred embodiment, the device includes a single sensor adapted to measure over at least three non-coincident detection axes. Alternatively, two detection sensors may be provided, the first sensor being adapted to measure over two first detection axes and the second sensor being adapted to measure over a single second detection axis, the second detection axis being non-coincident with the two first detection axes. Alternatively, three sensors may be provided, each adapted to measure over a single non-coincident detection axis.

[0021] Preferably, the one or more sensors are arranged on a structural element that can be attached in front of the wheel rim by a mounting element and / or behind the wheel spindle by a specific support, or alternatively, the one or more sensors are arranged on a bracket that can be connected to the wheel spindle.

[0022] Advantageously, the device further comprises a wheel force and / or momentum converter comprising an electromechanical slip ring, said converter being placed between the structural element and the rim, if the structural element is provided.

[0023] Additional optical sensors, infrared temperature sensors, pressure sensors, accelerometers, gyroscopes, strain gauges, fiber optics and video sensors may be provided. [Brief explanation of the drawings]

[0024] These and other advantages and features of the present invention will become apparent from the following description of preferred embodiments given as non-limiting examples with reference to the accompanying drawings. [Figure 1A] FIG. 1A shows a front isometric view of an apparatus for dynamic measurement of a vehicle setup according to the present invention in a three-sensor embodiment. [Figure 1B] FIG. 1B shows a front isometric view of an apparatus for dynamic measurement of a vehicle setup according to the present invention in a two-sensor embodiment. [Figure 2] FIG. 2 shows a front isometric view of the device of FIG. 1 mounted on a wheel of a vehicle in a first embodiment. [Figure 3] FIG. 3 shows a rear isometric view of the device of FIG. 1 mounted on a vehicle wheel in a first embodiment. [Figure 4] FIG. 4 shows a rear isometric view of the device of FIG. 1 mounted on a vehicle wheel in a first embodiment. [Figure 5] FIG. 5 shows the diagram of FIG. 2 with the addition of the longitudinal and lateral planes of the vehicle's wheels and the plane defined by the ground. DETAILED DESCRIPTION OF THE INVENTION

[0025] 1 to 4, an apparatus for dynamic measurement of the setup of a vehicle 100 is provided.

[0026] In this disclosure, the term "vehicle" is used to denote any road vehicle having two, three, four or more wheels intended for the transport of passengers and / or goods. In particular, the present invention is applicable to motorcycles, quads, cars, vans and trucks, except for minor modifications and structural variations, and without departing from the scope of the present invention. For convenience, reference will be made to passenger vehicles, preferably with four wheels.

[0027] The term "setup" refers to the set of angles and adjustments of the wheels, suspension groups and tires of a vehicle that define its behavior and performance on a road or track. In particular, in this disclosure, as mentioned above, "setup" refers to the orientation of the so-called "center plane" of the wheels of a vehicle with respect to three Cartesian axes, i.e., angular and alignment parameters, defined by the wheels and suspension of the vehicle, including the camber angle, caster angle and toe angle, the so-called wheel load radius, i.e., the distance between the wheel hub and the ground under vehicle load conditions, the kinematic steering axis of the wheel and all its derivatives or tire dynamics.

[0028] On the other hand, the term "dynamic measurements" refers to measurements made during the actual use and driving conditions of the vehicle, in particular during acceleration, braking and steering, which, due to the stresses induced, significantly affect the weight, forces and position of the center of gravity of the vehicle, as well as the geometric shapes and alignments of the same components and deformations of the materials.

[0029] The device 100 adapted to be applied to a wheel 1 of a vehicle comprises one or more non-contact detection sensors 4 for measuring the set-up as described above with respect to a plane defined by the ground surface [S].

[0030] According to the invention, said one or more sensors 4 define at least three mutually non-coincident detection axes to determine a plane [T] that intersects the wheel 1 laterally.

[0031] Also according to the invention, said one or more sensors 4 are integral with said plane T and with a longitudinal section L passing through the centre line of said wheel 1 .

[0032] The term "integral with" means, as known to those skilled in the art, rigid constraints with respect to a reference body. In this case, the expression "integral with planes [T] and [L]" should be understood to mean, by extension, that one or more sensors are integrally connected to the "wheel group", i.e., for example, spindle 3.

[0033] As mentioned above, this measurement has clear advantages in terms of accuracy and consistency of the measurements, as well as in terms of availability and progress with respect to known techniques. Indeed, the possibility of measuring these parameters directly with respect to the ground, rather than with respect to the chassis or body of the vehicle, avoids the occurrence of problems associated with reference systems of the vehicle, as well as the subsequent processing of the data obtained by complex and inaccurate calculations and simulation algorithms.

[0034] That is, the plane of the wheel 1 [T] is measured relative to the ground [S], rather than an imaginary plane passing through other elements of the vehicle which may be subject to deformations, misalignments and consequently lead to inaccuracies in the measurement.

[0035] With reference to FIG. 5, [S], [T] and [L] indicate a plane defined by the ground, a transverse plane relative to the wheel 1 and a longitudinal plane passing through the centerline of said wheel 1, respectively.

[0036] Here, the presence of one or more sensors 4 defining at least three detection axes allows the definition of a plane [T] from which the definition of plane [L] can be directly derived. From the relative orientation of these two planes [T, L] with respect to the ground, measured by their instantaneous distance from plane [S], all parameters defining the vehicle setup contemplated herein can be directly and accurately derived.

[0037] On the other hand, prior art devices generally only have two measurement points, lack the possibility of triangulating the distance, and are unable to provide such measurements. Furthermore, known devices are not integral with the wheels and have at least some degrees of freedom associated with the above-mentioned drawbacks.

[0038] According to a preferred embodiment of the present invention, the device 100 comprises a single sensor 4 adapted to measure over at least three detection axes that are not coincident with one another.

[0039] The term "sensing axes" in this disclosure does not refer to Cartesian or coordinate axes, but rather to axes defined by design choice to allow the definition of the cross section [T] of the wheel 1, said axes not necessarily being orthogonal between themselves.

[0040] Also preferably, the device 100 can comprise two detection sensors 4a, 4b, the first sensor 4a being a sensor configured to measure over two first detection axes and the second sensor (4b) being a sensor configured to measure over one second detection axis, also known as a "spot" sensor, which, according to the invention, does not coincide with the two first detection axes.

[0041] Alternatively, the three sensors 4a, 4b, 4c are configured to measure a single detection axis that is not coincident with one another (spot sensors).

[0042] It will be apparent to those skilled in the art that in some embodiments, more than three sensors 4, for example four or five sensors, may be provided without departing from the scope of the present invention.

[0043] The one or more sensors 4 are preferably optical sensors, however other types of non-contact sensors can be implemented such as, but not limited to, infrared sensors, ultrasonic sensors, scanners, among others.

[0044] In a preferred embodiment of the invention, the device 100 comprises a structural element 2 on which said one or more sensors 4 can be arranged.

[0045] The term "structural element" refers to a structure or frame configured to support the components of the present invention, particularly all of the sensors described above and below.

[0046] For example, as shown in Figures 1A and 1B, which show an embodiment with three sensors 4a, 4b and 4c and an embodiment with two sensors 4a, respectively, the structural element 2 can be attached to the front of the rim (1b) of the wheel 1 by means of a mounting element 5. Additionally or alternatively, a constraint can be provided to the rear of the spindle (3) of the wheel 1 by means of a specific support (3b).

[0047] It will be clear to those skilled in the art that design variations in the geometry and arrangement of the structural element 2, the number and location of fixing points of said element 2 relative to the wheel 1 can be envisaged based on the type of vehicle to which the device 100 is to be mounted, the dimensions of the wheel 1, the available space, the geometry of the spindle 3, etc.

[0048] In particular, the structural element 2 can be designed as a modular element and / or can be provided with adjustable or retractable components or can have variable geometric shapes and dimensions so that it can be adapted to vehicle specifications.

[0049] In the preferred embodiment shown in Figure 1A, the first optical sensor 4a and the second optical sensor 4b may be mounted on a first arm of the structural element 2, which is arranged in front of the wheel 1 and longitudinally relative to the direction of movement of the vehicle, while the third optical sensor 4c may be mounted on a second arm of the structural element 2, which is arranged behind the wheel 1, in a position opposite to the second optical sensor 4b.

[0050] In a second preferred embodiment shown in FIG. 1B, the first optical sensor 4a can be installed on a first arm of the structural element 2 arranged in front of the wheel 1 and longitudinally relative to the direction of movement of the vehicle, while the second optical sensor 4b can be installed on a second arm of the structural element 2 arranged behind the wheel 1 and in a position opposite to the second optical sensor 4b.

[0051] 2 and 3 show the device 100 mounted on a wheel 1 of a vehicle in a preferred embodiment.

[0052] As expected, the device 100 provides a mounting element 5 by which the structural element 2 can be connected to the wheel 1 of the vehicle. The mounting element 5 preferably comprises a flange 5a, for example of a metal material, suitable for fitting into a suitable seat 1c formed in the rim 1b, and a connecting element 5b, for example a pin, suitable for engaging in the seat 2b of the structural element 2.

[0053] To ensure that there is a degree of freedom between the structural element 2 and the wheel 1, i.e. to ensure that the wheel 1 can rotate freely without dragging the entire device 100, a mechanical bearing is provided inside the seat 2b.

[0054] In a further preferred embodiment, shown in FIG. 4, said one or more sensors 4 may be arranged on suitable brackets 3 c, 3 d connectable to the spindle 3 of said wheel 1 .

[0055] It will be apparent to those skilled in the art that the location of the one or more sensors 4 will depend greatly on the geometry of the vehicle to which the device 100 is mounted, and that other configurations and arrangements than those described are possible without departing from the scope of the present invention.

[0056] Additionally, the device 100 according to the invention may include a force and / or momentum transducer, known in the prior art and configured to measure the forces and momentum generated by the wheels and transmit them in the form of electromagnetic or electrical signals from the rotating to the fixed body, thanks to the presence of electromechanical slip rings.

[0057] In the above-described embodiment, for example, said force and / or momentum converter (not shown) can be placed between the structural element 2 and the wheel rim 1b.

[0058] Additionally, the device 100 according to the invention can include a two-axis optical sensor 6 mounted on the structural element 2. Said sensor is useful for measuring, for example, distance, acceleration, angular velocity of rotation of the wheels, as well as the so-called slip angle of the tires.

[0059] Finally, the device 100 is configured to cooperate with and possibly integrate with other conventional sensors and measurement systems, such as, purely by way of example, dynamic wheels, infrared temperature, pressure, acceleration sensors, gyroscopes, strain gauges, fiber optic sensors, and video sensors.

[0060] The data generated by the apparatus 100 according to the present invention can be acquired and processed by suitable electronic and / or IT devices and computing algorithms, as well as analyzed by a PC.

[0061] It will be apparent that what has been described in this application is given by way of non-limiting example only and that variations and modifications may be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.

[0062] For example, design variations in the geometry and arrangement of the structural elements 2 and mounting elements 5, as well as their attachment points to the wheel 1, are contemplated based on the type of vehicle to which the device 100 is to be mounted, the dimensions of the wheel 1, the available space, the geometry of the hub carrier 3, etc.

[0063] The device 100 according to the invention is configured to provide accurate measurements of the main aspects and parameters that define the vehicle setup and its associated behavior on the road. Measurements of the wheel and suspension orientation in dynamic conditions are carried out by sensors integrated in the wheel plane, measuring the distance of the wheel hub from the ground under load, analyzing the tire dynamics, and the possibility of having at least three measurement points that are not coincident with each other for triangulation makes it possible to obtain an accurate and consistent analysis of the vehicle's kinematics and dynamics.

Claims

1. 1. An apparatus for dynamic measurement of a set-up of a vehicle having two, three, four or more wheels, the apparatus being adapted to be mounted on a wheel of the vehicle and comprising one or more non-contact detection sensors for measuring said set-up relative to a plane defined by the ground; The one or more sensors define at least three non-coincident detection axes to determine a plane that laterally intersects the wheel, the one or more sensors being integral with the plane and a longitudinal plane passing through the centerline of the wheel.

2. 10. The apparatus of claim 1, comprising a single sensor adapted to measure across at least three non-coincident sensing axes.

3. 2. The apparatus of claim 1, comprising two detection sensors, a first sensor configured to measure across two first detection axes and a second sensor configured to measure across a single second detection axis, the second detection axis not coincident with the two first detection axes.

4. 10. The apparatus of claim 1, comprising three sensors adapted to measure across a single, non-coincident axis of detection.

5. 5. The device according to claim 1, wherein the one or more sensors are arranged on a structural element that can be attached in front of the rim of the wheel by means of a mounting element and / or behind the spindle of the wheel by means of a specific support.

6. 6. An apparatus according to any one of claims 1 to 5, wherein the one or more sensors are arranged on a bracket connectable to a spindle of the wheel.

7. 7. The apparatus of claim 1, wherein the one or more sensors are optical sensors.

8. 8. The device according to claim 1, further comprising a wheel force and / or momentum converter comprising an electromechanical slip ring, the converter being located between the structural element and the rim, if the structural element is provided.

9. The apparatus of claim 1 , further comprising a two-axis optical sensor mounted on the structural element.

10. 10. The apparatus of claim 1, further comprising an infrared temperature sensor, a pressure sensor, an accelerometer, a gyroscope, a strain gauge, an optical fiber, and a video sensor.

11. 11. Apparatus according to any one of claims 1 to 10, further comprising electronic and / or computer equipment for acquiring and processing data.

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