Autonomous vehicle with wind sensor

Abstract

The invention proposes a piloted autonomous vehicle comprising a main body (10), motorized means (30) for moving the vehicle, the vehicle being capable of undergoing attitude variations during its movement, the vehicle further comprising a wind sensor attached to the main body. According to the invention, the vehicle includes a motorized system (60) for mounting the sensor on the wind, capable of correcting measured attitude variations of the vehicle in order to maintain the wind sensor in a set orientation. Applications include, in particular, drones, for piloting and / or collecting information affected by wind. (Fig. 3)

Description

Title of the invention: Autonomous machine with wind sensor Field of invention

[0001] The present invention relates to an autonomous machine, for example of the aerial drone type (or UAV for “Unmanned Aerial Vehicle” in English), equipped with a wind sensor. State of the art

[0002] Drones are known that are equipped with a wind sensor, and the data collected from this sensor can be used, for example, for environmental measurements. The actual wind is measured by differentiating between the measured relative wind and the speed of the craft, known from the inertial unit on board the craft.

[0003] On-board wind sensors must be lightweight so as not to overload the machine, and as accurate as possible. In addition, some sensors are sensitive to tilt, so if they are not positioned according to a reference orientation, wind measurements can become inaccurate and sometimes unusable.

[0004] A solution to this problem may consist of stabilizing the attitude of the craft carrying the sensor, but this constraint is generally incompatible with the attitude variations inherent in the movements of the craft and the need to counter the wind. Summary of the invention

[0005] The present invention aims to propose an autonomous flying machine equipped with a wind sensor, which overcomes the aforementioned problems.

[0006] To this end, a piloted autonomous machine is proposed, comprising a main body, motorized means for moving the machine, the machine being capable of undergoing variations in attitude during its movement, the machine further comprising a wind sensor secured to the main body, the machine being characterized in that it comprises a motorized system for mounting the sensor on the wind, capable of correcting measured variations in attitude of the machine in order to maintain the wind sensor in a set orientation.

[0007] Certain preferred but non-limiting aspects of the apparatus include the following additional features, taken individually or in any combination that the person skilled in the art will understand to be technically compatible with each other:

[0008] * the motorized system comprises a two-axis joint and motors rotation drive of the joint along the two axes.

[0009] * the two axes are horizontal in a reference position of the machine, and or thogonal between them.

[0010] * the motorized mounting system comprises two arms, one of which is integral with the main body of the machine and the other of which carries the wind sensor, the arms being connected by the joint, the latter comprising a pair of stirrups secured to each other and secured in rotation to two motors mounted respectively on the two arms.

[0011] * the motors are servomotors.

[0012] * the joint comprises a body with two motors attached.

[0013] * the body defines a housing for motor control circuitry.

[0014] * the motorized system comprises a first arm mounted on a main body of the machine and a part of which located at a distance from said body is rotationally fixed to the output shaft of a first motor.

[0015] * the first arm is configured so that the center of gravity of the moving assembly that this carrying arm is located substantially vertically above an anchoring region of the first arm on the main body.

[0016] * the motorized mounting system comprises a second arm carrying the sensor of wind and an intermediate part of which is integral in rotation with the output shaft of the second motor.

[0017] * the second arm has a counterweight, said intermediate part of the second arm being close to a center of gravity of the assembly formed by the second arm, its counterweight and the wind sensor.

[0018] * the motors are brushless motors.

[0019] * the wind sensor comprises a combination of ultrasonic sensors. Brief description of the drawings

[0020] Non-limiting embodiments of the flying machine according to the present invention are now described in detail with reference to the accompanying drawings, in which

[0021] [Fig-1] is a schematic perspective view of a machine according to the invention,

[0022] [Fig.2] is a detailed perspective view of a wind capture system according to a first embodiment, and

[0023] [Fig.3] is a detailed perspective view of a wind capture system according to a second embodiment.

[0024] Detailed Description of Preferred Embodiments

[0025] With reference to [Fig. 1], an autonomous flying machine or drone is shown, here of the six-rotor type, which comprises a main body 10 and a set of arms 20 supporting as many rotors 30 each equipped with a propeller 31 and a motor 32.

[0026] The electronic circuitry of the machine and the batteries are housed in the main body. The latter may be equipped with a nacelle 40 or other support for the mechanical and electrical connection of accessories such as cameras, sensors, etc.

[0027] The device also comprises a wind sensor 50 carried by a support 60 and arranged above the central body 10, at a distance from the propellers 31 which is sufficient to prevent the air stirred from top to bottom by the propellers to ensure lift from disturbing the wind measurement. This distance may vary depending on the type of craft, but is typically between 1 and 1.5 times the diameter of the propellers 31, this being however in no way limiting. The support comprises a two-axis joint 70 as will be seen in detail later.

[0028] The wind sensor is for example a wind sensor equipped with a set of ultrasonic sensors, in particular the TriSonica® sensor marketed by the company Anemoment LLC, 353 Main Street, Longmont, CO 80501, United States of America. Capable of determining the wind vector to which it is exposed along three axes. The wind sensor may also be capable of measuring the temperature, humidity, pressure and dew point of the air, and also be equipped with a compass function.

[0029] Referring now to [Fig. 2], a first version of a stabilized system for mounting a wind sensor on a machine is shown in perspective. Thus, the support 60 comprises a first fixed arm 61 oriented generally vertically (in the reference position, at rest, of the machine), fixed at its base to the main body of the machine. At the upper end of the arm 61 is provided a two-axis motorized joint generally designated by the reference 70. This joint comprises a first motor 71 mounted fixedly on the upper end of the arm 61 and of which an output shaft 72 defines a first horizontal pivot axis A1 of the joint and drives a double stirrup 73 in rotation along this axis.At a vertical distance above the axis Al, the stirrup 73 is connected to an upper arm 62 of the support via a second motor 74, at the level of an output shaft 75 of this motor which defines a second horizontal pivot axis A2 of the joint, orthogonal to the first axis AL.

[0030] On a plate provided at the upper end of the arm 62 is fixedly mounted, possibly via damping elements, the wind sensor 50, here of the aforementioned type.

[0031] On the arm 61 is fixed a housing 80 housing the control circuitry of the motors 71, 74, as well as an inertial unit making it possible to deliver attitude data from the machine, in particular attitude and inclination. This circuitry receives as input flight data from the machine and in particular attitude and inclination data. In this way the stability mounting device is independent of the machine. Alternatively, this data can come from an inertial unit pre-existing on the machine.

[0032] The circuitry controls the motors 71, 74 so that, during flight, the upper arm 62 maintains a vertical attitude, apart from control uncertainties. The two axes A1, A2 correspond, for example, to the axes X, Y of the machine according to the standard designation (X: main axis corresponding to the nominal direction of advance, Y: transverse horizontal axis), so that the motors 71 and 74 allow to compensate for variations in the trim and inclination of the machine depending on the trajectory, with possible “crab” advancement, and the wind.

[0033] In this way, the sensor 50 maintains its optimal working orientation, to deliver wind speed and orientation data that is as accurate as possible.

[0034] The motors 71, 74, in this configuration, must be chosen to deliver sufficient torque for the aforementioned orientation maintenance control. Typically, servomotors are chosen.

[0035] We will now describe with reference to [Fig. 3] a second embodiment making it possible to reduce the torque to be exerted by the motors, and therefore to use motors of different technologies, typically smaller, lighter, while improving the quality of stabilization and limiting wear phenomena.

[0036] The support 60 here comprises a lower arm 161 comprising a base 161a and an angled extension 161b, and a generally vertical upper arm 162, located in the extension of the base 161a or at least in this region, so as to bring the center of gravity of the mobile assembly on this lower arm closer to the axis of the base 161a and thus limit the overhanging forces.

[0037] A joint 170 with two articulation axes connects the arms 161 and 162. It comprises a first motor 171 mounted at the end of the bent extension 161b opposite the base 161a, oriented substantially horizontally along an axis AL. The output shaft (not visible) of the motor 171, oriented along this same axis, is engaged with said end of the bent extension 161b.

[0038] The motor 171 is integral with a main body 172 defining a housing 173 receiving trim and tilt compensation control circuitry. In an opposite region of the housing 172 is mounted a second motor 174 whose output shaft (not visible), arranged along a horizontal axis A2 perpendicular to the axis A1, is engaged with a mount 175 fixed in an intermediate position of the arm 162.

[0039] The arm 162 carries at its upper end a plate 162a on which the wind sensor 50 is mounted, while it is provided at its lower end with a counterweight 162b, the fixing position of the mount 175 being substantially at the height of the center of gravity of the assembly consisting of the arm 162 (including its counterweight) and the wind sensor 50.

[0040] In the same spirit, the elements are designed and dimensioned so that the center of gravity of the assembly mounted at the upper end of the bent part 161b of the arm 161 (namely the two motors 171, 174, the housing 172 and the circuitry it contains, the arm 162 and the sensor 50) is substantially aligned with the axis AL

[0041] In this way the torque required at the motors 171 and 174 is lowered, and in particular it becomes possible to use brushless motors. English) much more compact, lighter and consuming less current, to the benefit of the autonomy of the machine.

[0042] Of course, the present invention is in no way limited to the embodiments described above and shown in the drawings, but those skilled in the art will be able to make numerous variations and modifications thereto.

[0043] Furthermore, the invention can be implemented with vehicles of all types in which variations in attitude are observed during movement, in particular land or water vehicles, whether manned or not.

Claims

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5. Claims Autonomous piloted machine, comprising a main body (10), motorized means (30) for moving the machine, the machine being capable of undergoing variations in attitude during its movement, the machine further comprising a wind sensor (50) secured to the main body, the machine being characterized in that it comprises a motorized system (60) for mounting the sensor on the wind, capable of correcting measured variations in attitude of the machine in order to maintain the wind sensor in a set orientation, the motorized system (60) comprising: - a joint (170) with two axes (Al, A2), - motors (171, 174) for driving the joint in rotation along the two axes, the joint comprising a body (172) to which the two motors (171, 174) are integral, - a first arm (161) mounted on a main body (10) of the machine and a part of which located at a distance from said body is rotationally fixed to the output shaft of a first motor (171) and configured so that the center of gravity of the mobile assembly (171, 172, 174, 162, 50) that this arm carries is located substantially vertically above an anchoring region of the first arm (161) on the main body, - a second arm (162) carrying the wind sensor (50) and of which an intermediate part (175) is integral in rotation with the output shaft of the second motor (174), the second arm having a counterweight (162b), said intermediate part (175) of the second arm being close to a center of gravity of the assembly formed by the second arm (162), its counterweight (162b) and the wind sensor (162a, 50). Machine according to claim 1, characterized in that the two axes (A1, A2) are horizontal in a reference position of the machine, and orthogonal to each other. Machine according to one of claims 1 and 2, characterized in that the body defines a housing (173) for a motor control circuitry. Machine according to one of claims 1 to 3, characterized in that the motors (171, 174) are brushless motors. Machine according to one of claims 1 to 4, characterized in that the wind sensor (50) comprises a combination of ultrasonic sensors.

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