A SYSTEM AND A RELATIVE METHOD FOR DETECTING POLLUTING SUBSTANCES USING A REMOTELY PILOTED VEHICLE FROM A HAPTIC COMMAND DEVICE

Abstract

A system (10) for the remote detection of substances, comprising a vehicle (20) that is mobile in space and remote-piloted using a control device (40) with a haptic interface suitable to return a force feedback to a user of the con?trol device (40), wherein the vehicle (20) is equipped with a position sensor (22) and a sensor (21) for detecting a physical quantity whose intensity de?pends on the distance of at least one substance present in a detection point located in a vicinity of the position of the vehicle (20).

Claims

1. A system (10) for the remote detection of substances, comprising a vehicle (20) that is mobile in space and remote-piloted using a control device (40) with a haptic interface suitable to return a force feedback to a user of the control device (40), wherein the vehicle (20) is equipped with a position sensor (22) and a detection sensor (21) of a physical quantity of at least one substance present in a detection point located in a vicinity of a position of the vehicle (20).

2. The system (10) according to claim 1, characterised in that it comprises an electronic control unit (30) operatively connected to the position sensor (22), to the detection sensor (21) and the control device (40) and configured so as to carry out a detection cycle which comprises steps of: measuring a value of a physical quantity of the substance at the detection point; determining a force feedback modulus to be returned to a user of the control device (40) by means of a haptic interface on the basis of the value of the measured physical quantity; and controlling the control device (40) to return the force feedback with the determined modulus.

3. The system (10) according to claim 2, wherein the detection cycle further comprises the steps of: comparing the value of the measured physical quantity with a threshold value thereof: if the value of the physical quantity is greater than the threshold value, setting the position of the vehicle (20) corresponding to the detection point where the value of the physical quantity was measured as a reference position and defining an area of the space containing the reference position and a current position of the vehicle (20); and controlling the control device (40) to return a force feedback with non-zero modulus for positions of the vehicle (20) comprised within the defined area.

4. The system (10) according to claim 3, wherein at each detection cycle the electronic control unit (30) is configured so as to update the threshold value with the measured value of the physical quantity if the measured value of the physical quantity is greater than the threshold value.

5. The system (10) according to claim 2, wherein the non-zero modulus of the feedback force is a function that increases as the distance of the current position from the set reference position increases.

6. The system (10) according to claim 2, wherein the modulus of the feedback force is zero in the set reference position.

7. The system (10) according to claim 2, wherein the force feedback modulus is zero for positions of the vehicle located outside the defined area.

8. The system (10) according to claim 1, wherein the vehicle is an unmanned air vehicle (20).

9. The system (10) according to claim 1, wherein the detection sensor (21) is an X-ray or gamma-ray sensor and the measured physical quantity is the radiation intensity of the substance.

10. A method for the remote detection of substances using a detection system provided with a vehicle (20) that is mobile in space and remote-piloted using a control device (40) with a haptic interface suitable to return a force feedback to a user of the control device (40), wherein the vehicle (20) is equipped with a position sensor (22) and a sensor (21) for detecting a physical quantity of at least one substance present in a detection point located in a vicinity of a position of the vehicle (20), wherein the method comprises carrying out a detection cycle which comprises steps of: measuring a value of a physical quantity of the substance at the detection point; determining a force feedback modulus to be returned to a user of the control device (40) by means of a haptic interface on the basis of the value of the measured physical quantity; and controlling the control device (40) to return the force feedback with the determined modulus.

11. The method according to claim 10 characterised in that the detection cycle comprises the steps of: comparing the value of the measured physical quantity with a threshold value thereof: if the value of the physical quantity is greater than the threshold value, setting the position of the vehicle (20) corresponding to the detection point where the value of the physical quantity was measured as a reference position and defining an area of the space containing the reference position and a current position of the vehicle (20); and controlling the control device (40) to return a force feedback with non-zero modulus for positions of the vehicle comprised within the defined area.

12. The method according to claim 11, characterised in that it comprises, at each detection cycle, a step of updating the threshold value with the measured value of the physical quantity if the measured value of the physical quantity is greater than the threshold value.

13. The method according to claim 11, wherein the non-zero value of the feedback force modulus is a function that increases as the distance of the current position from the set reference position increases.

14. The method according to claim 12, which comprises a step of calculating the feedback force modulus through the following formula: $f=\frac{?}{||r-u||}?\left[\begin{array}{ccc}0& 1& 0\\ 0& 0& -1\\ -1& 0& 0\end{array}\right]?\left[\begin{array}{ccc}?& 0& 0\\ 0& ?& 0\\ 0& 0& 0\end{array}\right]?\left[\begin{array}{c}{r}_x-u_x\\ r_y-u_y\\ r_z-u_z\end{array}\right],$ wherein, f is the feedback force modulus, ? is a selection value, ? is a correlation function, r is the reference position of coordinates (r.sub.x,r.sub.y,r.sub.z) and u is the current position of the vehicle (20) of coordinates (u.sub.x,u.sub.y,u.sub.z).

15. The method according to claim 14, wherein the correlation function ? is given by the following equation: $?=\frac{f_{\max }}{L^2}.Math.{d^2?\left(r,u\right)}_{\mathrm{xy}}$ wherein f.sub.max is a predetermined maximum value of the feedback force modulus, d(r,u).sub.x,y is the distance of the current position of the vehicle (20) from the set reference position, L is a predetermined constant.

16. The method according to claim 14, wherein the selection value ? is set according to the following condition: $?=\{\begin{array}{cc}0& \mathrm{se}.Math..Math.{d?\left(r,u\right)}_{\mathrm{xy}}>L\\ 1& \mathrm{se}.Math..Math.{d?\left(r,u\right)}_{\mathrm{xy}}?L\end{array}.$

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further characteristics and advantages of the invention will be apparent from reading the flowing descriptionprovided by way of non-limiting examplewith reference to the figures illustrated in the attached drawings.

[0041] FIG. 1 is a schematic diagram of a detection system according to an embodiment of the invention.

[0042] FIG. 2 is a flow chart of a detection system according to an embodiment of the invention.

BEST EMBODIMENT OF THE INVENTION

[0043] With particular reference to such figures, a system for detecting polluting and/or radioactive substances is indicated in its entirety with 10.

[0044] The system 10 may be used in contexts such as the ones listed below in an exemplifying but non-exhaustive list, including: [0045] environmental decontamination following a radioactive fall-out caused by a nuclear accident or war event; [0046] monitoring nuclear power plant sites; [0047] monitoring areas suspected of having environmental contamination (e.g. illegal disposal sites); [0048] periodical monitoring of waste disposal sites to ensure quality environment for the citizens; [0049] monitoring industrial storage sites with contamination potential, such as depots for ferrous material, wood material, or building material in general.

[0050] The system 10 comprises an unmanned vehicle, preferably an unmanned air vehicle 20. However, it cannot be ruled out that the vehicle can be of the land or floating or submarine vehicle type.

[0051] The air vehicle 20 comprises a driving unit and remote activatable piloting means, as better described hereinafter.

[0052] The air vehicle 20 is equipped with a detection sensor 21, which can be mounted on the air vehicle 20, for example so as to be vertically faced downwards. The detection sensor 21 is suitable to detect/measure a physical quantity C whose intensity depends on the distance from the substance (i.e. it decreases on the detection point where the substance is present).

[0053] The detection sensor 21 is for example a radiation sensor in solid state, for example an X-ray (or gamma ray) sensor for detecting a physical quantity C, i.e. a radiation intensity, of a substance (polluting or radioactive) present in a detection point positioned in the proximity of the detection sensor 21 and thus the air vehicle 20.

[0054] The detection point is for example defined along a radius of action of the detection sensor, for example at the point of intersection of the ground with the radius (vertical) of action of the detection sensor 21.

[0055] Alternatively, the detection sensor 21 could be a sensor suitable to detect the concentration of a chemical substance (organic or inorganic), the detected physical quantity C possibly being the concentration of the substance, for example a polluting substance, in this case.

[0056] The air vehicle 20 is also equipped with a position sensor 22 for establishing a current position u of the air vehicle 20.

[0057] The position sensor 22 may be any device suitable to provide information regarding the position of the position sensor 22. Thus, the current position u of the air vehicle 20 can be established from this position. Preferably, the position sensor 22 provides three position coordinates (u.sub.x,u.sub.y,u.sub.z). The position sensor 22 may comprise a global positioning system (GPS) for providing the horizontal position coordinates u.sub.x and u.sub.y, for example within +/?2 m of tolerance, and a device for measuring the differential pressure to provide the vertical position coordinate u.sub.z (altitude), for example within +/?1 cm of tolerance. The system 10 further comprises an electronic control unit 30.

[0058] The electronic control unit 30 is operatively connected to the detection sensor 21 and to the position sensor 22, so as to receive the signals detected and processed by it.

[0059] The electronic control unit 30 is for example arranged in a remote position with respect to an air vehicle 20 and it is suitable to receive/transmitthrough suitable means for transceiving signals and/or datathe signals and/or data detected by the sensors 21,22 in real time, for example, in wireless mode; in this case, the air vehicle 20 is provided a signal transceiver connected to the sensors 21,22.

[0060] It cannot be ruled out that the electronic control unit 30 can be arranged on board the air vehicle 20 and communicate, through a suitable transmitter, the processed data to a remote control station.

[0061] The electronic control unit 30 for example comprises a processor (or microprocessor) and a memory.

[0062] The electronic control unit 30 is configured to receive information regarding the current position u from the position sensor 22. The processor of the electronic control unit 20 is configured to periodically associate the current position data u coming from the position sensor 22 with data regarding the measured values of the physical quantity C (of the radioactive and/or polluting substance or a substance to be monitored in any case) coming from the detection sensor 21 to create the combined data representing the physical quantity C at the detection point. The combined data may be created any time the detection sensor 22 is read. Preferably, the processor may be configured to associate the current position data u with data regarding the measured values of the physical quantity C at least once per second, preferably once every 500 ms and more preferably approximately once every 100 ms. The system 10 also comprises a control device 40 configured to remote-pilot the air vehicle 20.

[0063] The control device 40 can for example be held by an operator in a remote position with respect to the current position u of the air vehicle 20.

[0064] The control device 40 for example comprises a haptic interface configured to return a force feedback to a user of the control device.

[0065] The control device 40 may be of the type described in patent no EP1690652, which shall be deemed incorporated hereto for reference, and known under the trade name NOVINT FALCON.

[0066] In particular, the control device 40 according to the preferred embodiment comprises a base element 41 and a mobile element 42 (which can be held by the operator). The base element 41 and the mobile element 42 are connected through three kinematic chains 43.

[0067] Every kinematic chain 43 comprises a first arm (main) and a second arm (secondary).

[0068] Every second arm may be considered to be a parallelogram including two connection rods. Every connection rod is coupled, at an end thereof, with the mobile element 42 by means of a joint or hinge. Each connection rod is coupled, at the opposite end thereof, with an end of the first arm by means of a joint or hinge.

[0069] Each second arm, in particular each connection rod, has two degrees of freedom rotational on both ends. In order to provide this functionality, the coupling of the second arms to the mobile element 42 and the relative first arms may be obtained using cardan elements or parallel or non-parallel pairs of connection or rotational articulations, such as ball bearings, sliding bearings or flexible hinges.

[0070] Alternatively, each second arm, in particular each connection rod, may have three degrees of freedom rotational on both ends. In order to provide this functionality, the coupling of the second arms to the mobile element 42 and the relative first arms may be obtained by means of ball joints at one or both ends

[0071] At the end opposite to the end coupled with the relative arm, each first arm is coupled with a mounting element, which is in turn fixedly mounted on the base element 41. The mounting element and the base element may also be made of a single piece.

[0072] Each first arm is coupled with the relative mounting element thereof so that each first arm can be rotated or oscillated with respect to the mounting element and, thus, with respect to the base element 41 by means of a rotary shaft.

[0073] A rotary actuator 44 is mounted on each mounting element so as to rotate the first arm with respect to the mounting element and, thus, with respect to the base element 41.

[0074] Rotary actuators 44 may be, for example, DC standard motors or brushless motors.

[0075] Elements for detecting the angular position (not shown) of each first arm, such as potentiometers, optical encoders, magnetic encoders, are preferably associated to the output shafts or any other part of the rotary actuators 44 and they are suitable to provide angular information

[0076] The rotary actuators 44 and the detection elements are operatively connected, for example by wireless means through a suitable transceiver or by means of a cable (for example USB), to the electronic control unit 30 and/or to a further control unit for piloting the air vehicle 20 (i.e. for controlling the control means and the driving unit of the air vehicle).

[0077] Basically, by holding the mobile element 42 and actuating it in the space surrounding the base element 41, the operator controls the movement of the air vehicle 20 to perform corresponding movements in the airspace.

[0078] The movement of the mobile element 42 is controlled by means of detection elements controlling the rotation imparted by the user to the single output shafts of the rotary actuators 44.

[0079] The rotary actuators 44 are configured to define the force feedback (i.e. a vector defined by a modulus f, by a direction and an orientation) to the user as outlined below.

[0080] Basically, the force feedback could be a force resistant to the movement imparted by the user to the mobile element 42 or an active force of the rotary actuators 44 such to push the mobile element (if released or countering the movement imparted by the user) towards a reference point of the space, for example an inoperative configuration of the mobile element 42.

[0081] The electronic control unit 30 is, for example, configured to established (calculate) the force feedback modulus f as described below and control the rotary actuators 44 of the control device 40 so as to apply the established force feedback modulus f to the mobile element 42 of the control device.

[0082] The air vehicle 20, for the detection purposes according to the present invention, may be defined as a level flight, i.e. at a constant height (altimetry), thus wherein the vertical position coordinate u.sub.z is equal to a constant (non-zero) for example pre-established by means of a preliminary study of the area to be flown over.

[0083] Once the vehicle 20 begins the flight for example over a pre-established detection area the electronic control unit 30 is configured to perform a plurality of detection cycles as described hereinafter.

[0084] For example, each detection cycle provides for that the electronic control unit 30 performs the step of measuring (block S1), by means of the detection sensor 21, a (first) value of the physical quantity C of a substance (radioactive or polluting) at the detection point, i.e. associated to the position r where the air vehicle 20 is located at the time of detection, as described above; according to the value of the physical quantity C, the electronic control unit 30 is configured to establish, for example calculate, a force feedback modulus f to be returned to the user of the control device 40 by means of the haptic interface.

[0085] More in detail, the electronic control unit 30 is configured to compare (block S2) the measured value of the physical quantity C with a threshold value thereof.

[0086] For example, at the first detection, the threshold value is set to the full radiation intensity perceivable at the flight height u.sub.z, i.e. the full radiation of the ground perceivable at such flight height u.sub.z; alternatively, the threshold value may be a value of the physical quantity (radiation intensity) greater than the value of full intensity radiation and deemed critical for such area.

[0087] Should the value of the physical quantity C be lower than the threshold value, the electronic control unit 30 is configured to repeat an additional detection cycle.

[0088] On the other hand, should the value of the physical quantity C be greater than the threshold value, the electronic control unit 30 is configured to set (block S3) the position r of the air vehicle 20 corresponding to the point of detection where such value of the physical quantity C was measured, as a reference position r. According to such reference position r, the electronic control unit 30 is configured to establish (block S4) an area (virtual) of the airspace of the air vehicle 20 containing the reference position r and the current position u of the air vehicle 20.

[0089] For example, the defined area may be a circle on the horizontal plane centred in the reference position r, in which the radius L of the circle is a constant pre-established, for example through pre-calibration operations, carried out at the experimental stage, and stored in the memory of the electronic control unit 30.

[0090] The defined area may for example be any desired geometric shape (for example flat and horizontal) containing the reference position r therein or on the perimeter thereof.

[0091] Thus, the electronic control unit 30 is configured to establish, for example calculate, (block S6) the force feedback modulus f to be returned to the user of the control device 30 by means of the haptic interface.

[0092] More in detail, the modulus f is calculated through the following formula:

[00004]$f=\frac{?}{||r-u||}?\left[\begin{array}{ccc}0& 1& 0\\ 0& 0& -1\\ -1& 0& 0\end{array}\right]?\left[\begin{array}{ccc}?& 0& 0\\ 0& ?& 0\\ 0& 0& 0\end{array}\right]?\left[\begin{array}{c}{r}_x-u_x\\ r_y-u_y\\ r_z-u_z\end{array}\right],$

wherein, f is the force feedback modulus, ? is a selection value, ? is a correlation function, r is the reference position of coordinates (r.sub.x,r.sub.y,r.sub.z) and u is the current position of the air vehicle 20 of coordinates (u.sub.x,u.sub.y,u.sub.z).

[0093] Advantageously, the correlation function ? is obtained from the following equation:

[00005]$?=\frac{f_{\max }}{L^2}.Math.{d^2?\left(r,u\right)}_{\mathrm{xy}},$

wherein f.sub.max is a pre-established maximum value of the force feedback modulus, for example established through experimental activities and stored in the memory of the electronic control unit 30, d(r,u).sub.x,y is the Euclidean distance solely regarding the coordinates x,y of the current position u of the air vehicle 20 from the set reference position r, L is the radius of the defined area.

[0094] The selection value ?, which is a value number selectively equal to 1 or 0, is set based on the following conditions:

[00006]$?=\{\begin{array}{cc}0& \mathrm{se}.Math..Math.{d?\left(r,u\right)}_{\mathrm{xy}}>L\\ 1& \mathrm{se}.Math..Math.{d?\left(r,u\right)}_{\mathrm{xy}}?L\end{array}.$

[0095] Basically, the force feedback modulus f is a non-zero value proportional to the square of the distance of the current position u from the reference position r at any position of the air vehicle 20 within the defined area, except for the position coinciding with the reference position r, where the modulus f is equal to zero. In addition, the force feedback modulus f is zero at the positions of the air vehicle 20 found outside the defined area.

[0096] Thus, the electronic control unit 30 is configured to control (block S7) the rotary actuators 44 of the control device 40 to returnto the usera force feedback with modulus f that is: [0097] non-zero for the positions of the air vehicle 20 comprised in the defined area and different from the reference position r, and [0098] zero in the reference position r and outside the defined area.

[0099] At each detection cycle in which the measured value of the physical quantity C is greater than the threshold value, the electronic control unit 30 is configured, furthermore, to update (block S8) the threshold value by replacing it with the measured value of the physical quantity C.

[0100] Otherwise, i.e. in cases where the measured value of the physical quantity does not exceed the threshold value, the threshold value remains intact with respect to one established at the previous detection cycle.

[0101] Thus, at the subsequent detection cycle, the reference position r is changed only in case of measurement, by the detection sensor 21, of a value of the physical quantity C greater than the previously measured value of the physical quantity C.

[0102] The invention thus conceived is susceptible to numerous modifications and variants all falling within the inventive concept.

[0103] In addition, all details can be replaced by other technically equivalent elements.

[0104] Basically, the materials used as well as the shapes and contingent dimensions, may vary according to the needs without departing from the scope of protection of the claims that follow.