WO2015009222A1

WO2015009222A1 - Overturn warning in vehicles

Info

Publication number: WO2015009222A1
Application number: PCT/SE2014/050818
Authority: WO
Inventors: Fredrich Claezon; Carl Fredrik Ullberg; Mikael Lindberg
Original assignee: Scania Cv Ab
Priority date: 2013-07-18
Filing date: 2014-06-30
Publication date: 2015-01-22
Also published as: DE112014002961B4; SE1350902A1; SE538987C2; DE112014002961T5

Abstract

A method (300) and calculating unit (120) for detecting overturning of a vehicle (100). The method (300) comprises determination (301 ) of a normal plane (140) by means of measurement of a distance (A1) in the vertical direction of the vehicle between a 3D camera (110-1, 110-2) contained in the vehicle (100) and an underlying surface (130) when the vehicle (100) is in a horizontal position. The method (300) also comprises measurement (302) by means of the 3D camera (110-1, 110-2) of the distance (A2, A3) between the 3D camera (110-1, 110-2) and the surface (130) underlying the vehicle. The method (300) further comprises calculation (303) of the difference in distance between the measured (302) distance (A2, A3) and the distance (A1 ) to the determined (301 ) normal plane (140) and detection (304) that the vehicle (100) is about to overturn when the calculated (303) difference in distance exceeds a threshold value.

Description

OVERTURN WARNING IN VEHICLES

TECHNICAL FIELD OF THE INVENTION

The invention concerns a method and a calculating unit associated with a vehicle. More specifically the invention concerns a mechanism for detecting an overturn of a vehicle.

BACKGROUND

A vehicle can come to tilt in relation to the roadway plane because of, e.g. a heavy asymmetrically placed load and/or uneven underlying surface, e.g. in connection with driving into a ditch or the like.

Vehicle refers in this context to, for example, a goods vehicle, long-haul semi, pickup truck, transport vehicle, wheel loader, bus, all-terrain vehicle, tracked vehicle, tank, four-wheeler, car or other similar motorized manned or unmanned means of transport adapted for land-based geographical movement.

Such tilting can in turn cause the vehicle to overturn, which can injure the vehicle driver seriously. In the case of heavy vehicles, overturn accidents are presumably the most common cause of death among drivers.

A crash sensor comprising a type of accelerometer and gyro that senses accelera- tions and rotational accelerations is often used to detect that the vehicle is about to overturn. A vehicle model can be used that is calculated so as to emit a signal when a prevailing angle of inclination and acceleration exceed the position wherein the vehicle is laterally stable, and thus about to overturn. Because a heavy vehicle overturns relatively slowly, one often waits a long time into the process to avoid risking the triggering of side airbags of the vehicle too soon, or in error.

Calibrating a crash sensor for managing overturn accidents of this type requires a plurality of crash tests in which accelerometer data are measured for each position and vehicle type on which one wishes to install a crash sensor and overturn protection. This is extremely expensive and time-consuming.

The crash sensor with accelerometer and gyro cannot detect per se whether the vehicle is at risk of overturning into a rock, and thus will not trigger side airbags in time in connection with such an accident. This can potentially be solved by the supplemental installation of one or a plurality of pressure sensors, which are installed, for example, in the doors. These have the task of sensing when the side of the vehicle will strike the ground so as to trigger the side airbags earlier in such cases than they otherwise would be triggered. These are cases in which the vehi- cle overturns against, for example, a stone or object that is protruding from the ground plane.

However, installing such extra pressure sensors requires extra cabling that must be run in the doors. Extra work steps and material costs are consequently necessitated. A crash sensor is an expensive component that also has a very limited area of application and can only detect overturning of the vehicle and not, for example, that another vehicle is about to drive into its side, or that the host vehicle is about to drive into an obstacle etc.

It is clear that much still remains to be done to improve the detection of hazards that occasion the triggering of subsequent crash protection in a vehicle and also lower the cost thereof.

SUMMARY OF THE INVENTION

One object of this invention is consequently to improve the detection of the over- turning of a vehicle so as to solve at least one of the aforementioned problems and thereby achieve a vehicle improvement.

According to a first aspect of the invention, this object is achieved by means of a method in a calculating unit for detecting overturning of a vehicle. The method comprises the determination of a normal plane by measuring a distance in the vertical direction of the vehicle between a 3D camera contained in the vehicle and an underlying surface when the vehicle is in a horizontal position. The method further comprises measurement by means of the 3D camera of the distance between the 3D camera and the underlying surface for the vehicle. The method further comprises calculation of the difference in distance between the measured distance and the distance to the determined normal plane. The method also comprises detection that the vehicle is about to overturn when the calculated difference in distance exceeds a threshold value. According to a second aspect of the invention, this object is achieved by means of a calculating unit for detecting overturning of a vehicle. The calculating unit comprises a signal receiver arranged so as to receive a measurement value from a 3D camera contained in the vehicle. The calculating unit further comprises a processor circuit arranged so as to determine a normal plane based on measurement of a distance, in the vertical direction of the vehicle, between a 3D camera contained in the vehicle and a surface on which the vehicle is in a horizontal position. The processor circuit is also arranged so as to calculate the difference in distance between the measured distance to the underlying surface and the distance to the determined normal plane. The processor circuit is further arranged so as to detect that the vehicle is about to overturn when the calculated difference in distance exceeds a threshold value.

Using a 3D camera to detect overturning of the vehicle rather than a conventional crash sensor enables more reliable detection of an overturn, and an expanded functionality, as protruding objects or irregularities in the underlying surface, which are at risk of penetrating or striking the cab, can be detected. This provides opportunity to trigger side airbags and/or seatbelt pre-tensioners earlier than usual. Areas of application above and beyond the detection of overturning are also achieved as compared to conventional crash sensors, such as detection of another road- user at an angle concealed from the driver, measurement of a distance to a lead vehicle in order to warn the driver that the distance is too short, and/or adaptation of the vehicle cruise control to the velocity of a lead vehicle. Repurposing the 3D camera so as to measure and determine the inclination of the vehicle according to the methods described herein thus makes it possible to reduce the number of sensors in the vehicle, which leads to lower material costs, fewer installation steps and a lower manufacturing cost for the vehicle, as fewer components need to be kept in stock and installed in the vehicle.

Another advantage is that the 3D camera is relatively insensitive in terms of where it is mounted on the vehicle, as long as it has an unobstructed field of view. Fast and simple installation is thereby enabled, which also results in lower manufacturing costs. Furthermore, because neither the mounting height nor the placement of the 3D camera is sensitive, fewer trials are required to calibrate the algorithms than is the case with conventional crash sensors, thereby lowering costs and providing a shorter time-to-market for such overturn warning capability. An improvement of the vehicle is achieved thereby. Other advantages and additional new features will be evident from the following detailed description of the invention.

LIST OF FIGURES

The invention will now be described in greater detail with reference to the panying figures, which illustrate various embodiments of the invention:

Figure 1 A illustrates a vehicle with a sensor, shown in profile.

Figure 1B illustrates a vehicle with a sensor, viewed from behind.

Figure 2A illustrates a vehicle with a sensor, viewed from behind, with an angu- lar deviation toward the horizontal plane.

Figure 2B illustrates a vehicle with two sensors, viewed from behind, with an angular deviation toward the horizontal plane. Figure 2C illustrates a vehicle with two sensors, viewed from behind, with an angular deviation toward the horizontal plane where detection of an object on the underlying surface is being performed.

Figure 3 is a flow diagram that illustrates an embodiment of a method. Figure 4 is an illustration of a calculating unit in a system according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention is defined as a method and a calculating unit for determining an an- gular deviation in the horizontal plane of a vehicle, which can be realized in any of the embodiments described below. However, this invention can be realized in many different forms and is not to be viewed as limited by the embodiments described herein, which are intended rather to elucidate and clarify various aspects of the invention. Additional aspects and features of the invention can be evident from the following detailed description when it is considered in combination with the accompanying figures. However, the figures are to be viewed solely as examples of various embodiments of the invention, and are not to be viewed as limitative of the invention, which is limited solely by the accompanying claims. Furthermore, the figures are not necessarily drawn to scale and are, unless otherwise specified, intended to illustrate aspects of the invention conceptually.

Figure 1A shows a vehicle 100 in a direction of travel 101. Said direction of travel 101 refers to an existing or planned direction of travel 101 , i.e. the vehicle 100 can be in motion in the direction of travel 101 , or be standing still, prepared for a planned movement in the direction of travel 101 or to move in the directly opposite direction, i.e. to reverse.

The vehicle 100 has a cab 105 in which the vehicle driver is normally situated while driving the vehicle 100. At least one 3D camera 110-1 is mounted on or in the vehicle 100, e.g. in or on the cab 105. Said 3D camera 110-1 can contain or consist of, for example, a radar measuring device, a laser measuring device such as a Light Detection And Ranging (LIDAR) device, sometimes also called a LADAR or laser-radar, a camera such as a Time-of-Flight camera (ToF camera), a stereo camera, a light- field camera, or a similar device configured for distance determination.

A LIDAR is an optical measuring instrument that measures properties of reflected light in order to determine the distance and/or other properties of a remote object. The technology is reminiscent of radar, (Radio Detection and Ranging), but light is used instead of radio waves. The distance to an object is typically measured by measuring the time delay between an emitted laser pulse and the registered reflection from the object.

A ToF camera is a type of camera that takes a sequence of images and measures a distance to an object, based on the known speed of light, by measuring the time it takes for a light signal to pass between the camera and the object, e.g. by measuring the phase shift between the emitted light signal and a received reflection of the light signal from the object.

More than one 3D camera 110-1 is mounted on the vehicle 100 in certain embodiments. One advantage of having more than two 3D cameras 110-1 is that more reliable distance determinations can be made, and a larger area can be monitored by an additional 3D camera. Another advantage is that an assessment of the inclination of the vehicle can be made in multiple dimensions, such as two or three dimensions according to certain embodiments. In such embodiments with more than one 3D camera 110-1 , the 3D cameras can consist of the same type of 3D camera or of different types of 3D cameras according to different embodiments.

The vehicle 100 also contains a calculating unit 120, which is arranged so as to receive measurement data from the 3D camera 110-1 , and to perform calculations based on said measurement data. For example, a distance to the surface 130 underlying the vehicle can be measured by the 3D camera 110-1 and sent to the cal- culating unit 120, which can compare this measurement value with a measurement value made on a horizontal plane.

According to certain embodiments, a 3D camera 110-1 can be mounted on each side of the cab 105 so that it is possible to detect whether the vehicle 100 is about to overturn. The 3D camera 110-1 can measure the distance to the surface 130 underlying the vehicle, e.g. continuously or at a given time interval. Determining a normal plane when the vehicle 100 is traveling on a horizontal surface, determining the distance to said normal plane and comparing this distance to the distance measured later makes it possible to calculate the risk that the vehicle 100 will overturn, e.g. when a given limit value is exceeded.

One advantage of disposing the 3D camera 110-1 inside the cab 105 of the vehicle 100 rather than on the outside of the vehicle 100 is that the 3D camera 110-1 is better protected there against external damage such as dirt, splatter and the like, as well as against theft, damage and other harm. The reliability of the 3D camera 110-1 can thus be improved and the service life of the 3D camera 110-1 extended compared to when it is disposed on the outside of the vehicle 100.

On the other hand, the 3D camera 110-1 can, in certain embodiments, be disposed high up near the roof of the vehicle 100. A long range is thereby achieved for the 3D camera 110-1. Such a high placement offers a degree of protection against splash from other vehicles, and against theft and damage etc.

According to certain embodiments, the 3D camera 110-1 can be arranged so as to detect an object at the side of the vehicle 100 that is protruding from the underlying surface 130 and poses a risk of striking the cab 105 and thereby injuring the driver before the vehicle 100 has overturned completely. Such a protruding object can consist of any arbitrary object, such as a rock, another vehicle, a road sign, a building, a tree, a pet animal or another similar object. It has no significance to the invention whether the protruding object is in motion or standing still. The invention is also independent of whether the host vehicle 100 is standing still or in motion according to certain embodiments. One advantage of using a 3D camera 110-1 to detect overturning of the vehicle 100 compared with prior art crash sensors based on accelerometers and gyros is that a 3D camera 110-1 has additional areas of application above and beyond overturn detection. For example, the 3D camera 110-1 can detect pedestrians, other vehicles that are approaching the host vehicle 100 etc, thereby enabling greater functionality than offered by a conventional crash sensor. A side airbag adapted for overturn accidents has a greater potential to save lives than does a steering wheel-mounted airbag in a heavy vehicle such as a goods vehicle, long- haul semi or bus, and it is consequently important that it work as well as possible. At the same time, it is naturally deleterious in terms of traffic safety if an airbag is triggered by mistake in the vehicle 100 while it is moving.

For example, the 3D camera 110-1 can be disposed in or on the vehicle 100 for another purpose, such as to measure distances to lead vehicles with a view to warning the driver if the distance is too short, and/or to adapt the vehicle cruise control to the velocity of a lead vehicle. Another conceivable purpose is to detect an object that appears in front of the vehicle 100 and warn the driver about it, or to initiate automatic braking, for example.

Repurposing the 3D camera 110-1 to measure and determine the inclination of the vehicle according to the methods described herein thus makes it possible to re- duce the number of sensors in the vehicle 100, which leads to lower material costs, fewer installation steps and lower manufacturing costs for the vehicle 100, in that fewer components need to be stocked and installed in the vehicle 100.

Another advantage is that the 3D camera 110-1 is largely insensitive to where it is mounted in the cab 105, as long as it has an unobstructed field of view. Fast and simple installation is thus enabled, which leads to lower manufacturing costs.

Another advantage of the 3D camera 110-1 compared to conventional crash sensors is that it can, as described above, detect whether the vehicle 100 is about to roll into a protruding object, thereby providing opportunity to trigger side airbags and/or seatbelt pre-tensioners earlier than usual. Furthermore, because neither the mounting height nor the placement of the 3D camera 110-1 is sensitive, fewer tests are required to calibrate the algorithms, which lowers costs and yields a shorter time-to-market for such overturn warning capability. Figure 1B shows the vehicle 100 in Figure 1A, viewed from behind. The 3D camera 110-1 measures the vertical distance A1 to the surface 130 underlying the vehicle when the vehicle 100 is on a horizontal surface. Vertical refers here to a direction that is essentially perpendicular to the direction of travel of the vehicle 100. A normal plane 140 can thereby be established, along with the reference distance A1 to said normal plane 140.

According to various embodiments, such determination of the reference distance A1 and the normal plane 140 can be performed, for example, in connection with the manufacture of the vehicle, during inspection, in connection with a software update for the vehicle 100, or when it can be determined that the vehicle 100 is on a horizontal surface, e.g. via measurements by means of the 3D camera 110-1 or another sensor in the vehicle.

Figure 2A shows the vehicle 100 in Figure 1A and Figure 1 B, viewed from behind, but now about to overturn. The 3D camera 110-1 measures the distance A2 to the underlying surface 130. This measurement value can then be sent to the calculat- ing unit 120 via a wire-bound or wireless interface.

Such a wireless interface can be based on, for example, any of the following technologies: Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Code Division Access (CDMA), (CDMA 2000), Time Division Synchro- nous CDMA (TD-SCDMA), Long Term Evolution (LTE); Wireless Fidelity (Wi-Fi), defined by the Institute of Electrical and Electronics Engineers (IEEE) standards 802.11 a, ac, b, g and/or n, Internet Protocol (IP), Bluetooth and/or Near Field Communication, (NFC), or a similar communication technology according to various embodiments. According to certain other embodiments, the calculating unit 120 and the 3D camera 110-1 are arranged for communication and information transfer over a wire- bound interface. Such a wire-bound interface can comprise a communication bus system consisting of one or a plurality of communication buses for connecting to- gether a number of electronic control units (ECUs), or control units/controllers, and various components and sensors localized on the vehicle 100, such as the 3D camera 110-1.

The calculating unit 120 and the 3D camera 110-1 are arranged so as to communicate both with one another so as to receive signals and measurements val- ues and optionally so as also to trigger a measurement, e.g. at a given time interval. Furthermore, the calculating unit 120 and the 3D camera 110-1 are arranged so as to communicate, for example, via the vehicle communication bus, which can consist of one or a plurality of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or some other bus configuration.

When the measurement value that represents the measured distance A2 between the 3D camera 110-1 and the surface 130 underlying the vehicle is received in the calculating unit 120, it can then be compared to the previously determined distance A1 to the normal plane 140. According to certain embodiments, the detec- tion that the vehicle 100 is about to overturn can be made when the difference between the distances A1 and A2 exceeds a certain limit value, such as 50 cm, 100 cm, 130 cm, 180 cm, 250 cm or some other arbitrary limit value between any of these exemplary limit values. In certain embodiments such a limit value can very with, for example, vehicle type, vehicle model and load. Furthermore, the measurement by means of the 3D camera 110-1 of the distance A2 to the surface 130 underlying the vehicle can be used to calculate an angle a of the vehicle inclination in relation to the determined normal plane 140.

The angle a can be calculated from the following trigonometric equation (the sinus theorem for a right triangle):

where the distance D designates the distance between the contact surface of the outer wheel with the underlying surface 130 and the point on the normal plane 140 at which the 3D camera 110-1 makes its readings. Said distance D, which is es- sentially constant, can be determined or measured in advance in connection with a calibration and stored as a constant.

According to certain embodiments, the detection that the vehicle 100 is about to overturn is made when the angle a of the inclination of the vehicle exceeds a certain limit value, such as 10°, 25°, 42°, 60° or another limit value between any of these exemplary limit values. In certain embodiments such a limit value can vary with, for example, vehicle type, vehicle model and load.

The illustrated example of the angular deviation a of a vehicle in Figure 2A is merely an arbitrary illustration.

Figure 2B shows the vehicle 100 in Figure 1A, Figure B and/or 2A, viewed from behind, but now about to overturn, and further containing a 3D camera 110-2 that measures the distance A3 to the underlying surface 130. This measurement value can then be sent to the calculating unit 120 via a wire-bound or wireless interface according to the foregoing description and used together with or instead of the measurement value A2 measured by means of the first 3D camera 110-1. According to certain embodiments, the second 3D camera 110-2 can be disposed on the other side of the vehicle 100 in relation to the first camera 110-1 , for example as shown in Figure 2B, or on the same side as the first camera 110-1.

One advantage of having a second 3D camera 110-2 as a supplement to the first camera 110-1 is that more reliable measurement data can be obtained, and it is possible to avoid measurements being made in a ditch, pit or other hollow along the side of the roadway 130.

Yet another advantage of having a second 3D camera 110-2 as a supplement to the first camera 110-1 and having them be disposed on opposite sides of the vehi- cle 100 is that an object that protrudes from the underlying surface 130 and threatens to penetrate the cab 105 and injure the driver [can be detected]. This is shown in greater detail in Figure 2C.

Figure 2C shows how the second 3D camera 110-2 detects an object 150 that, were the vehicle 100 to overturn, could penetrate the cab 105 and injure the driver. One or several measures can thus be taken to protect the driver, such as triggering a side airbag, tensioning the seatbelt, deploying a protective curtain on the side window in the cab 105, moving the driver seat in the direction opposite to the one in which the vehicle 100 is falling, triggering a catapult mechanism in the driv- er seat and ejecting the driver from the cab 105, or the like.

Figure 3 illustrates an exemplary embodiment of the invention. The flow diagram in Figure 3 illustrates a method 300 for detecting the overturning of a vehicle 100. The method 300 can be performed entirely or partly in a calculating unit 120 in the vehicle 100, based on one or more measurements made by means of a 3D cam- era 110-1 in the vehicle 100. Alternatively, the method 300 can be performed in a system in the vehicle 100, which system comprises a 3D camera 110-1 and a calculating unit 120. In certain embodiments, the calculating unit 120 can be contained in a 3D camera 110-1 in the vehicle 100.

The vehicle 100 can contain two 3D cameras 110-1 , 110-2 in certain embodi- ments. Such 3D cameras 110-1 , 110-2 can consist of a Time of Flight, ToF, camera; a stereo camera; and/or a light-field camera.

To be able to detect overturning of the vehicle 100 correctly, the method 300 can comprise a number of steps 301-305. However, it should be noted that the described steps 301-305 can be performed in a chronological order other than that indicated by the numerical order, and that certain of them can be performed in parallel with one another, according to various embodiments. Furthermore, certain steps can be performed in certain but not necessarily all embodiments, such as step 305. The method 300 comprises the following steps: Step 301

A normal plane 140 is determined by measuring a distance A1 in the vertical direction of the vehicle between a 3D camera 110-1 , 110-2 contained in the vehicle 100 and an underlying surface 130 when the vehicle 100 is in a horizontal position.

5 According to certain embodiments, a horizontal position can be determined via measurement by means of the 3D camera 110-1 , 110-2, via measurement by means of a second sensor in the vehicle 100 or by measuring in relation to a reference surface that is determined to be horizontal, such as a flat stretch of road.

Step 302

10 The 3D camera 110-1 , 110-2 measures the distance A2, A3 between the 3D camera 110-1 , 110-2 and the surface 130 underlying the vehicle.

In certain embodiments, the vehicle 100 can contain two 3D cameras 110-1 , 110- 2, and the measurement of the distance A2, A3 can be made by means of 3D cameras 110-1 , 110-2, respectively.

15 The measurement by means of the 3D camera 110-1 , 110-2 of the distance A2, A3 between the 3D camera 110-1 , 110-2 and the surface 130 underlying the vehicle can comprise distance measurements to a plurality of points on the underlying surface 130.

In certain embodiments, the measurement by means of the 3D camera 110-1 , 20 110-2 of the distance A2, A3 can be used to calculate an angle a of the vehicle inclination in relation to the determined normal plane 140.

The measurement by means of the 3D camera 110-1 , 110-2 of the distance A2, A3 between the 3D camera 110-1 , 110-2 and the surface 130 underlying the vehicle can be made continuously or at a given predetermined or configurable time 25 interval. Step 303

The difference between the measured 302 distance A2, A3 and the distance A1 to the determined 301 normal plane 140 is calculated.

In certain embodiments in which the vehicle 100 contains two 3D cameras 110-1 , 5 110-2 and the measurement of the distance A2, A3 is made using respective 3D cameras 110-1 , 110-2, the difference in distance between the respective measured 302 distance A2, A3 and the distance A1 to the determined 301 normal plane 140 Is calculated.

Step 304

10 When the calculated 303 difference in distance exceeds a threshold value, a detection that the vehicle 100 is about to overturn is made.

In certain embodiments in which the vehicle 100 contains two 3D cameras 110-1 , 110-2 and in which the measurement of the distance A2, A3 is made using respective 3D cameras 110-1 , 110-2, and the difference in distance between the 15 respective measured 302 distance A2, A3 and the distance A1 to the determined 301 normal plane 140 has been calculated, that the vehicle 100 is about to overturn 100 can be detected when both of these calculated distance differences exceed their respective thresholds simultaneously.

In certain embodiments in which the measurement by means of the 3D camera 20 110-1 , 110-2 of the distance A2, A3 has been used to calculate an angle a of the vehicle inclination in relation to the determined normal plane 140, a detection that the vehicle 100 is about to overturn can be made when the angle a of the vehicle inclination exceeds a threshold value.

In certain embodiments, the detection that the vehicle 100 is about to overturn can 25 be used to trigger a protective measure to protect the vehicle driver.

Step 305

This step can be performed in certain, but not necessary all embodiments. The 3D camera 110-1 , 110-2 can detect an object 150 on the underlying surface 130 that it is considered would strike the cab 105 of the vehicle in connection with an overturning of the vehicle 100.

In certain embodiments, the detection that it is considered that an object 150 on the underlying surface 130 would strike the cab 105 in connection with an overturning of the vehicle 100 can be used to trigger a protective measure to protect the vehicle driver.

Figure 4 shows an embodiment of a system 400 that includes a calculating unit 120. Said calculating unit 120 is configured so as to perform at least certain of the aforedescribed method steps 301-305 included in the description of the method 300 for detecting overturning of a vehicle 100.

According to certain embodiments, the calculating unit 120 can further be arranged so as to detect an object 150 on the underlying surface 130, which object it is considered would strike the cab 105 of the vehicle in connection with an over- turn, based on measurement values received from the 3D camera 110-1 , 1 0-2.

To be able to correctly detect overturning of the vehicle 100, the calculating unit 120 contains a number of components, which are described in greater detail in the text below. Certain of the described subcomponents are present in some, but not necessarily all embodiments. Additional electronics can also be present in the cal- culating unit 120 that are not entirely necessary for an understanding of the function thereof according to the invention.

The calculating unit 120 contains a signal receiver 410 arranged so as to receive a measurement value A2, A3 from a 3D camera 110-1 , 110-2 contained in the vehicle 100. According to certain embodiments, the measurement value A2, A3 can be sent from the 3D camera 110-1 , 110-2 to the signal receiver 410 in the calculating 120 via a wire-bound or wireless interface. The wireless network can be based on, for example, any of the following technologies: Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Code Division Access (CDMA), (CDMA 2000), Time Division Synchro- nous CDMA (TD-SCDMA), Long Term Evolution (LTE); Wireless Fidelity (Wi-Fi), defined by the Institute of Electrical and Electronics Engineers (IEEE) standards 802.11 a, ac, b, g and/or n, Internet Protocol (IP), Bluetooth and/or Near Field Communication, (NFC), or a similar communication technology according to various embodiments. According to certain other embodiments, the 3D camera 110-1 , 110-2 and the signal receiver 410 are arranged for communication and information transfer over a wire-bound interface. Such a wire-bound interface can comprise a communication bus system consisting of one or a plurality of communication buses for connecting together a number of electronic control units (ECUs), or control units/controllers, and various components and sensors localized on the vehicle 100. The vehicle communication bus can consist of one or a plurality of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or some other bus configuration; or of a wireless connection according, for example, to any of the foregoing wireless communication technologies. The calculating unit 120 further comprises a processor circuit 420, arranged so as to determine a normal plane 140 based on measurement of a distance A1 in the vertical direction of the vehicle between a 3D camera 110-1 , 110-2 contained in the vehicle 100 and an underlying surface 130 when the vehicle 100 is in a horizontal position. The processor circuit 420 is also arranged so as to calculate the difference in distance between a measured distance A2, A3 and the underlying surface 130 and the distance A1 to the determined normal plane 140. Furthermore, the processor circuit 420 is arranged so as to detect that the vehicle 100 is about to overturn when the calculated difference in distance exceeds a threshold value. The processor circuit 420 can consist of, for example, one or a plurality of a Central Processing Unit (CPU), microprocessor or other logic designed so as to inter- pret and carry out instructions and/or to read and write data. The processor circuit 420 can manage data for inflows, outflows or data-processing of data, including buffering of data, control functions and the like.

Embodiments of the calculating unit 120 can also include a memory unit 425, which in certain embodiments can consist of a storage medium for data. The memory unit 425 can consist, for example, of a memory card, flash memory, USB memory, hard drive or other similar data-storage unit, such as any of the group consisting of: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Eras- able PROM), etc. in various embodiments.

The calculating unit 120 can further comprise a signal transmitter 430 arranged so as to send a control signal to trigger a protective measure to protect the vehicle driver when a detection that the vehicle 100 is about to overturn and/or that an object 150 it is considered would strike the vehicle cab 105 in connection with an overturn has been made.

According to certain embodiments, the invention also contains a computer program for detecting overturning of a vehicle 100. The computer program is arranged so as to perform the method 300 according to at least one of the aforedescribed steps 301-305 when the program is executed in a processor circuit 420 in the calculating unit 120.

The method 300 according to at least one of the steps 301-305 for detecting overturning of the vehicle 100 can be implemented by means of one or a plurality of processor circuits 420 in the calculating unit 120 together with computer program code in order to perform one, some, certain or all of the steps 301-305 as de- scribed above. A computer program containing instructions for performing the steps 301-3015 when the program is loaded into the processor circuit 420 can thus [sic]. In certain embodiments, the aforedescribed computer program in the vehicle 100 is arranged so as to be installed in the memory unit 425 in the calculating unit, for example over a wireless interface.

In certain embodiments, the aforedescribed and discussed signal receiver 410, and/or signal transmitter 430 can consist of a separate transmitter and receiver. However, in certain embodiments the signal receiver 410 and signal transmitter 430 in the calculating unit 120 can consist of a transceiver that is adapted so as to send and receive radio signals, and wherein parts of the design, such as the antenna, are common to transmitter and receiver. Said communication can be adapted for wireless information transfer via radio waves, WLAN, Bluetooth or an infrared transceiver module. However, in certain embodiments the signal receiver 410 and/or signal transmitter 430 can alternatively be specially adapted for wire- bound information transfer, or alternatively for both wireless and wire-bound communication according to certain embodiments. The invention further comprises a system 400 for detecting overturning of a vehicle 100. Said system 400 comprises at least one 3D camera 110-1 , 110-2 and a calculating unit 120, as described above.

The system 400 can further comprise two 3D cameras 110-1 , 110-2 mounted in or on the vehicle 100. Such a 3D camera 110-1 , 110-2 can consist of, for example, a ToF camera, a stereo camera and/or a light-field camera according to various embodiments.

Some embodiments of the invention also include a vehicle 100 that contains a system 400 installed in the vehicle 100 for detecting overturning of the vehicle 100.

Claims

1. A method (300) in a calculating unit (120) for detecting overturning of a vehicle (100), wherein the method is (300) characterized by: determination (301) of a normal plane (140) by measuring a distance (A1) in the vertical direction of the vehicle between a 3D camera (110-1 , 110-2) contained in the vehicle (100) and an underlying surface (130) when the vehicle (100) is in a horizontal position, wherein the 3D camera (110-1 , 110-2) consists of a Time of Flight, ToF, camera; a stereo camera; and/or a light-field camera; measurement (302) by means of the 3D camera (110-1 , 110-2) of the distance (A2, A3) between the 3D camera (110-1 , 1 0-2) and the surface (130) underlying the vehicle; calculation (303) of the difference in distance between the measured (302) distance (A2, A3) and the distance (A1 ) to the determined (301 ) normal plane (140); detection (304) that the vehicle (100) is about to overturn when the calculated (303) difference in distance exceeds a threshold value.

2. The method (300) according to claim 1 , further comprising detection (305) by means of the 3D camera (110-1 , 110-2) of an object (150) on the underlying surface (130) that it is considered would strike the vehicle cab (105) in connection with an overturn.

3. The method (300) according to any of claim 1 or claim 2, wherein the vehicle (100) contains two 3D cameras (110-1 , 110-2), and wherein the measurement (302) of the distance (A2, A3) and the calculation (303) are performed for respective 3D cameras (110-1 , 110-2), and wherein the detection (304) consists in that the calculated (303) difference in distance exceeds the threshold value for both measurements simultaneously.

4. The method (300) according to any of claims 1-3, wherein the measurement (302) by means of the 3D camera (110-1 , 110-2) of the distance (A2, A3) between the 3D camera (110-1 , 110-2) and the surface (130) underlying the vehicle comprises distance measurements to a plurality of points on the underlying surface (130).

5. The method (300) according to any of claims 1-4, wherein the measurement (302) by means of the 3D camera (110-1 , 110-2) of the distance (A2, A3) is used to calculate an angle (a) of the vehicle inclination in relation to the determined normal plane (140), and wherein a detection (304) that the vehicle (100) is about to overturn is made when the angle (a) of the vehicle inclination exceeds a threshold value.

6. The method (300) according to any of claims 1-5, wherein the detection (304) that the vehicle (100) is about to overturn and/or the detection (305) of an object (150) that it is considered would strike the vehicle cab (105) in connection with an overturn are used to trigger a protective measure to protect the vehicle driver.

7. The method (300) according to any of claims 1-6, wherein the measurement (302) by means of the 3D camera (110-1 , 110-2) of the distance (A2, A3) between the 3D camera (110-1 , 110-2) and the surface (130) underlying the vehi- cle is made continuously.

8. A calculating unit (120) for detecting overturning of a vehicle (100), wherein the calculating unit (120) is characterized by: a signal receiver (410) arranged so as to receive a measurement value (A2, A3) from a 3D camera (110-1 , 110-2) contained in the vehicle (100), wherein the 3D camera (110-1 , 110-2) consists of a Time of Flight, ToF, camera; stereo camera; and/or light-field camera; a processor circuit (420) arranged so as to determine a normal plane (140) based on measurement of a distance (A1 ) in the vertical direction of the vehicle between a 3D camera (110-1 , 110-2) contained in the vehicle (100) and an underlying surface (130) when the vehicle (100) is in a horizontal position, and arranged so as to calculate the difference in distance between measured distances (A2, A3) to the underlying surface (130) and the distance (A1) to the determined normal plane (140), and further arranged so as to detect that the vehicle 5 (100) is about to overturn when the calculated difference in distance exceeds a threshold value.

9. The calculating unit (120) according to claim 8, further arranged so as to detect an object (150) on the underlying surface (130), which object it is considered would strike the vehicle cab (105) in the event of an overturn, based on

10 measurement values received from the 3D camera (110-1 , 110-2).

10. The calculating unit (120) according to claims 8-9, further comprising a signal transmitter (430) arranged so as to send a control signal to trigger a protective measure to protect the vehicle driver when a detection that the vehicle (100) is about to overturn and/or of an object (150) that it is considered would strike the

15 vehicle cab (105) in connection with an overturn has been made.

11. A computer program for detecting overturning of a vehicle (100) by means of a method (300) according to claims 1-7 when the computer program is executed in a processor circuit (420) in a calculating unit (120) according to any of claims 8-10.

20 12. A system (400) for detecting overturning of a vehicle (100), wherein the system (400) comprises: a 3D camera (110-1 , 110-2), consisting of a Time of Flight, ToF, camera; stereo camera; and/or light-field camera; and a calculating unit (120) according to any of claims 9-11.

25 13. The system (400) according to claim 12, further comprising two 3D cameras (110-1 , 110-2).

14. A vehicle (100) containing a system (400) according to any of claims 12- 13 and arranged so as to perform a method (300) according to any of claims 1-7 for detecting overturning of the vehicle (100).