AU2014202714A1 - Aircraft - Google Patents

Abstract

Abstract: Flight system comprising an aircraft equipped with at least four rotors having a payload, wherein a number of rotors rotate in one direction and a number of rotors rotate in another direction, as well as a remote control, wherein the aircraft is connected with the remote control via a transmitter/receiver unit respectively so as data can be transferred, wherein both the aircraft and the remote control respectively comprise a data processing means connected to the transmitter/receiver unit, wherein both the aircraft and the remote control comprise the same sensors for flight position recognition, wherein in the case of a change of angle of the remote control about its X- and/or Y- and/or Z-axis, the size of the change of angle correlates with a specified speed of the aircraft, wherein the specified speed corresponding to the change of angle is transmitted as a nominal value to the data processing means of the aircraft and/or the remote control, wherein the actual value of the speed of the aircraft is determined and compared with the nominal value in the data processing means, wherein by way of a control of the rotational speed of the rotors the thrust is changed to the extent that the nominal value of the speed matches the actual speed of the aircraft. 1968583v1 All. Fig4

Description

Title: Flight system Description [0001] The invention relates to a flight system comprising an aircraft equipped with at least four rotors having a payload, wherein a number of rotors rotate in one direction and a number of rotors rotate in another direction, as well as a remote control. [0002] Flight systems of the type mentioned at the outset are known in the form of toys, wherein the range of the aircraft is very limited, to some extent they can only be flown within closed spaces. The range of remote controller for controlling the flight movements is restricted, as is the flight height of the aircraft. In this respect, flight systems with aircraft used for commercial purposes are different. [0003] Such flight systems also comprise an aircraft and a remote controller, wherein the aircraft can receive a payload, for example a camera. The flight system is equipped such that the distance of the aircraft, also called a copter, is limited only by the range of the transmitter/receiver unit. The height to which such an aircraft can climb, is up to hundreds of meters. [0004] This means that very different requirements are thus placed on a flight system which is to serve commercial purposes, in stark contrast to the toys sector, in which such aircraft can only reach a height of about 3 to 5 m and can only be flown by sight, that is to say, at a distance of 20 to 30 m. This concerns not only the question of the output of the transmitter/receiver unit, but also the question of the controllability of such a copter. The copter, which comprises at least four rotors, of which some rotate in one direction and some in another direction, must hereby be in a controllable form such that information regarding the flight position and the speed, which are specified to the remote controller for the copter, are carried over exactly to the copter. This means that it must be ensured that what is set to nominal data in the remote controller for the copter is implemented directly by the drive system of the copter. [0005] A flight system capable of directly implementing the information specified by the remote controller and in particular with respect to speed and direction is characterised by the features of Claim 1. The flight system described is, however, not only capable of implementing the nominal values specified by the remote controller into actual values of the aircraft in a substantially identical manner, but is also capable of intuitively steering the aircraft by swivelling the remote controller about the X-, Y- and Z-axis. This means that the movements of the remote controller directly undergo their corresponding movements in the aircraft. In this respect, it is necessary that both the aircraft and the remote controller comprise corresponding sensors for recognising the flight position, such as for example accelerators and gyroscopes. Both the accelerators and the gyroscopes, of which preferably three are provided respectively, both in the remote control and in the aircraft, are respectively aligned in the direction of an axis in the Cartesian coordinate system. In this context, the following must be pointed out: determining the flight position of the copter would be theoretically conceivable even with three accelerators and a gyroscope. However, the accuracy of the determination of the flight position significantly increases when three gyroscopes are provided in addition to the three accelerators. The gyroscopes and the accelerators constitute an IMU (Initial Measurement Unit). This IMU enables the determination of translatory and rotatory movements. In order to carry out a measurement in all three spatial directions, three-axis sensors are preferably used, the three axes of which are arranged orthogonally to each other. The determination 2 of the flight position by the so-called IMU is an essential requirement in order to be able to fly the copter via the remote controller. In this context, it is provided that the data processing means of both the copter and also, advantageously, the remote controller comprise a control. Thus according to an advantageous feature of the invention, the control is implemented into the data processing means of the aircraft. [0006] This means that both the control of the speed and also of the flight direction takes place following receipt of the set value by the remote controller in the data processing means of the aircraft. This has the advantage that the aircraft responds substantially faster than in the case of an embodiment, in which the control for the aircraft would take place in the remote controller. However, the control in the data processing means requires a significant computing capacity, which means additional weight, which in turn, in the case of correspondingly weaker drive output of the aircraft can, however, lead to the control being arranged in the remote controller; that is to say, the processing of the data takes place in the data processing means of the remote controller. However, this also means that the data for determining the actual speed of the copter over ground, which are for example determined by means of GPS, radar sensors or an optical method such as the optical flow method, as well as the data for the flight position recognition are transmitted by the copter to the data processing means of the remote control, wherein the data processing means of the remote control calculates the values for thrust and flight position required for control by comparing nominal and actual values and transmits the calculated thrust and flight position values to the data processing means of the aircraft, wherein the data processing means of the aircraft implements these specifications for the flight position and thrust into the required rotational speeds of the individual rotors. In this context, the following must be pointed out: A copter, which consists of a housing having at least four, preferably however, six rotors, is inclined for flight in a direction corresponding to the latter direction. This means that individual rotors of the copter run slower than other rotors, wherein in this flight position, the speed of the rotors is, however, controlled for generating the required thrust. This means that when the angle of inclination of the remote controller is one amount for the speed of the copter, the specified speed values corresponding to the angle of inclination both of the copter and also the remote controller are stored in the data processing means. To this extent, the copter can be steered by movement of the remote controller about the X- and Y-axis into the corresponding direction. However, this means that both the copter and the remote controller have a corresponding coordinate system. [0007] According to a further feature of the invention, it is provided that the copter can rotate about its own axis. In order to determine the rotational speed as the actual speed, here in particular the gyroscopes serve as flight position sensors. It also applies here that the change to the angular position of the remote controller about the Z-axis constitutes a measurement for the rotational speed of the aircraft about its own axis. [0008] According to a further feature of the invention, the data processing means comprises a position control for aligning the aircraft in the horizontal position, which is connected to the sensors for flight position recognition and to the rotors. It has already been pointed out that the aircraft serve commercial purposes including recording images and also moving images, for example in the form of videos, using a camera arranged under the aircraft. In this respect, it is necessary that the aircraft be kept as still as possible in order to also enable the camera to focus an object. In order to carry out such a position control, in particular in the horizontal position, the sensors also serve for flight position recognition, namely the accelerators and 1968583v1 3 gyroscopes already mentioned. The control takes place in particular by controlling the rotational speed of the individual rotors. [0009] According to a further particular feature of the invention, it is provided that the sensors are supplemented by at least one magnetometer for flight position recognition, for example a magnetometer such as a compass enables the degree of the deviation in the alignment of the magnetometer in the direction north to be detected. [0010] The deviation can then be determined again in all three spatial directions, wherein a proportionally accurate alignment of the aircraft is possible in combination with the accelerators and gyroscopes already mentioned, in particular by the interaction between the gyroscopes, the accelerators and the at least one magnetometer. In order to determine the flight position of the aircraft, the gyroscopes and accelerators present in the aircraft and in the remote controller form a so-called IMU (Initial Measurement Unit), as already explained. Rotary and translatory movements are hereby determined. In order to be able to measure in all three spatial directions, so-called three-axis sensors are provided as gyroscopes and accelerators, which comprise three sensitive axes arranged orthogonally to each other. The accuracy of the determination of the flight position can ultimately be increased still further by using the data from a three-axis magnetometer in addition. Such a system, comprising both a magnetic sensor for determining the angular position and the gravitation as well as gyroscopes and accelerators, are known in the prior art as MARG systems (MARG = Magnetic Angular Rate and Gravity). Such MARG systems are capable of carrying out a complete determination of the orientation of the aircraft or of the remote controller relative to the direction of gravitation of the magnetic field of the earth. [0011] In this context, reference is made to the following publication: An efficient orientation filter for inertial and inertial/magnetic sensor arrays, Sebastian 0. H. Madgwick, April 30, 2010. [0012] The remote control itself, according to a further feature of the invention, is designed with a touch-sensitive screen as input and display means. Via this touch sensitive screen, that is to say, by way of the input means, the climb and/or descent speed can for example be specified to this extent. This means, in particular in relation to the descent speed of the aircraft, that this speed decrease cannot exceed a certain value from a certain minimum height above the ground, in order to ultimately avoid the aircraft crashing on the ground. To this extent, the aircraft also comprises sensors for determining the height, which are, for example designed as ultrasonic sensors and as sensors for determining the air pressure. Ultrasonic sensors hereby work satisfactorily up to heights of about 5 to 10 m above the ground, whereas air pressure sensors work in ranges above those of the ultrasonic sensors, wherein a certain overlap region is required in order to be able to obtain an accurate measurement in each case. [0013] According to a further feature of the invention, the aircraft displays distance sensors on its sides in order to be able to recognise lateral obstacles and also to determine the distance in relation to obstacles. Such obstacles are displayed on the touch-sensitive screen of the input means. [0014] The aircraft itself comprises a plurality of operating modes. An operating mode is characterised in that the flight directions of the aircraft are specified by the coordinate system of the remote controller. In this respect, the X, Y and Z-axis are input in a fixed manner in the remote controller. The position of this coordinate 1968583v1 4 system is specified to the aircraft. This specifically means that when the remote controller is swivelled about the X-axis, thus for example swivelled forward from the point of view of the pilot, the copter steers into the corresponding direction. It is clear from this that the pilot can always accurately pre-determine, through the movement of the remote controller, in which direction the aircraft will be actuated. [0015] A second operating mode is different to the latter operating mode, wherein the flight direction of the aircraft is specified by a coordinate system in the aircraft (First Person-View-System). In this respect, the control is carried out such that the coordinate system of the copter specifies the flight direction in X, Y and Z direction. The alignment of the coordinate system in the copter can hereby be quite different to that in the remote controller. This then specifically means that, for example when the remote controller is swivelled forward, the aircraft increases its speed, for example in a lateral direction. This means that the position of the coordinate system in the aircraft does not change, but rather remains fixed, just as the coordinate system in the remote controller does not change. [0016] According to a further feature of the invention, it is provided that the aircraft comprises at least one GPS receiver, which is connected to the data processing means of the aircraft and/or to the remote control. By way of a GPS it is possible to carry out a location determination of the copter during the flight. According to a further feature of the invention, it is provided that the remote control comprises at least one GPS receiver, which is connected to the data processing means in the remote control and to the copter. It is hereby possible to carry out a location determination of the aircraft relative to the remote controller, thus for example to determine the distance of the aircraft from the remote controller. [0017] Fig. 1 schematically shows the three axes of a remote controller, wherein the remote controller is designed in the manner of a tablet computer; [0018] Fig. 2 schematically shows the aircraft in a view from above; [0019] Fig. 3 shows a side view of the aircraft. [0020] The remote controller 10 is advantageously designed in the form of a tablet computer; that is to say the remote controller comprises a touch-sensitive screen, which serves for the input of data, but also the display of images from the camera on the copter. The tablet computer comprises a touch-sensitive screen, which means that communication with the aircraft is possible via this screen. In addition, the control of the copter takes place through movement of the tablet computer about the three axes of the Cartesian coordinate system, wherein for example a movement of the tablet computer about the X-axis effects a flight movement of the copter into the Y direction, wherein the speed of the copter increases with increasing inclination. The same applies for the movement of the tablet computer about the Y-axis. A movement in two spatial directions is thus possible. A movement of the aircraft about its own axis, that is to say the Z-axis, is effected by the tablet computer also being rotated about the Z-axis, wherein the size of the rotation correlates with the rotational speed of the copter. The climb height or the climb speed and the descent speed are input directly via the screen, for example in the form whereby in the case of a short, gliding movement of a finger on the screen forward/backward, a corresponding slow ascent/descent of the aircraft takes place. Long gliding finger movements, in contrast, effect a fast ascent or descent of the copter. [0021] Fig. 3 shows the copter in a view from above, wherein the copter comprises six rotors 5. In the centre, the copter 1 displays a housing 2 for receiving the data 1968583v1 5 processing means including the flight position sensors. The camera is for example located in the turret 3 under the copter. The batteries for driving the electric motors and also for operating the data processing means as well as the transmitter and receiver are located in the housing 2. The copter also comprises three legs 4, which are designed in a resiliently flexible manner in order to enable a soft landing of the copter. [0022] As already mentioned, both the copter and the remote controller comprise a plurality of, in particular, three accelerators and gyroscopes or, expressed in another way, three-axis sensors as gyroscopes and accelerators, wherein these sensors form an IMU system. Moreover, it is advantageously provided that the copter and the remote controller comprise a three-axis magnetometer in order to be able to take the data of the magnetometer into consideration for a more accurate determination of the orientation of the copter. These flight position sensors hereby form the MARG system. [0023] The control of the aircraft now takes place in a form, as depicted by way of example in the following. An operating mode is hereby set, in which the coordinate system of the remote controller is dominant for the control of the copter. [0024] The tablet computer is inclined for example about the X-axis by a certain amount, for example 150. If it is assumed that the aircraft is already located at a certain height in the air and that this is required as the starting position, then the copter will be slightly tilted, which in particular takes place by throttling a part of the motors of rotors, whereas in the case of another part, the output will be increased. The result of this is that the copter advances perpendicular to the X-axis of the tablet computer. The respective speed in this direction corresponds to the angular position of the tablet computer. The correlation between the angle and the speed are, for example stored in the remote controller. The same takes place for lateral movement of the tablet computer. In order to rotate the aircraft about its own axis, the tablet computer is also rotated about its own axis. The measurement of the rotation is hereby the measurement of the rotational speed of the aircraft. In order to launch and land the aircraft, the following is carried out: The starting speed is specified to the copter via the tablet computer by inputting via the touch-sensitive screen. The maximum height to which the copter should climb can also be specified. [0025] The situation is different when the copter is to land. The copter comprises, as mentioned at another point, sensors for determining the height above the ground, in particular an ultrasonic sensor and an air pressure sensor. The ultrasonic sensor is hereby provided for determining the height in the close range, that is to say, up to around 10 m, wherein determining the height is also carried out by the air pressure sensor. The descent speed can also be input via the tablet computer, wherein here however, the descent speed should not exceed a certain value when a certain minimum height is reached for safety reasons in order to avoid the destruction of the aircraft in the case it impacts the ground. The two height sensors, ultrasonic sensor and air pressure sensor, work at different height ranges, however they overlap one another. This means that in the case of falling below a certain minimum height, the ultrasonic sensor is used for height determination, while the air pressure sensor is used for determining greater heights. The remote controller advantageously also comprises sensors of this type. The reason for this is to be able to carry out a determination of the height above ground by means of the air pressure sensor. Alternatively however, the air pressure above the ground can also be determined and stored during the starting process. 1968583v1 6 [0026] At least two different modes are provided for the flight operation, as mentioned. A first mode is characterised, as was previously described, in that the position of the Cartesian coordinate system of the tablet computer always matches the position of the Cartesian coordinate system in the aircraft. This then means that when the computer, for example is rotated about its Z-axis, the coordinate system in the aircraft also correspondingly moves. However, this also means that a movement of the tablet computer about a certain axis always directly effects a movement of the aircraft into the swivelling direction. [0027] A second operating mode is characterised in that the position of the Cartesian coordinate system in the aircraft is dependent on the position of the tablet computer. This means that the position of the coordinate system is first specified to the aircraft, wherein when the tablet computer is moved about its X-axis, the aircraft possibly carries out a movement in the direction of the X-axis from the point of view of the pilot to the tablet computer. This operating mode is also known by the term "First Person-View-System". It can also be provided that the aircraft comprises at least one GPS receiver. The position of the aircraft can hereby be determined and displayed on the tablet computer. If the remote control also comprises a GPS receiver, then a position determination of the aircraft relative to the tablet computer is also possible. This means that it is possible to detect how far the aircraft is from the tablet computer. [0028] The aircraft itself comprises distance sensors on its front face, which prevent the aircraft impacting objects. Distance sensors are designed as ultrasonic or radar sensors and measure the distance of the aircraft in relation to possible obstacles. It also applies here that the speed in the direction toward the obstacle is reduced from a certain minimum distance such that a risk to the aircraft is not possible, even if the aircraft collides with the obstacle. List of reference numerals 1 copter 2 housing 3 turret 4 legs 5 rotors 10 remote controller 1968583v1

Claims (21)

1. Flight system comprising an aircraft equipped with at least four rotors having a payload, wherein a number of rotors rotate in one direction and a number of rotors rotate in another direction, as well as a remote control, wherein the aircraft is connected with the remote control via a transmitter/receiver unit respectively so as data can be transferred, wherein both the aircraft and the remote control respectively comprise a data processing means connected to the transmitter/receiver unit, wherein both the aircraft and the remote control comprise the same sensors for flight position recognition, wherein in the case of a change of angle of the remote control about its X- and/or Y and/or Z-axis, the size of the change of angle correlates with a specified speed of the aircraft, wherein the specified speed corresponding to the change of angle is transmitted as a nominal value to the data processing means of the aircraft and/or the remote control, wherein the actual value of the speed of the aircraft is determined and compared with the nominal value in the data processing means, wherein by way of a control of the rotational speed of the rotors the thrust is changed to the extent that the nominal value of the speed matches the actual speed of the aircraft.

2. Flight system according to Claim 1, characterised in that the determination of the actual speed of the aircraft over ground is carried out by means of GPS, radar sensors or an optical method, such as the optical flow method.

3. Flight system according to Claim 1 or 2, characterised in that the data for determining the actual speed of the aircraft are transmitted to the remote control, the data processing means of the remote control calculates the values for thrust and flight position required for control by nominal/actual comparison, the calculated thrust and flight position values are transmitted to the data processing means of the aircraft, wherein the data processing means of the aircraft implements these specification for flight position and thrust into the required rotational speeds of the individual rotors.

4. Flight system according to any one of the preceding claims, characterised in that the specified nominal speed corresponding to the change of angle of the remote control is transferred to the data processing means of the aircraft, wherein the control is implemented in the data processing means of the aircraft, which changes the rotational speed of the rotors to the extent that the nominal value of the speed matches the transmitted actual value.

5. Flight system according to any one of the preceding claims, characterised in that the determination of the actual rotational speed of the aircraft about the Z-axis takes place by means of flight position sensors.

6. Flight system according to any one of the preceding claims, characterised in that the data processing means comprises a position control for alignment of the aircraft in the horizontal position, which is connected to the sensors for flight position recognition and to the rotors.

7. Flight system according to any one of the preceding claims, characterised in that the sensors comprise accelerators and/or gyroscopes for flight position recognition.

8. Flight system according to Claim 7, characterised in that three accelerators are arranged both in the aircraft and in the remote controller, which are respectively aligned in a spatial direction. 1968583v1 8

9. Flight system according to Claim 7 or 8, characterised in that at least one, preferably however, three gyroscopes are arranged both in the aircraft and in the remote control, wherein one gyroscope is allocated to each spatial direction.

10. Flight system according to any one of the preceding claims, characterised in that the sensors comprise at least one magnetometer for flight position recognition.

11. Flight system according to any one of the preceding claims, characterised in that the remote control comprises a touch-sensitive screen as the input and display means.

12. Flight system according to Claim 11, characterised in that the climb and/or descent speed can be specified via the input means.

13. Flight system according to Claim 12, characterised in that the descent speed of the aircraft does not exceed a specified value from a certain height.

14. Flight system according to any one of the preceding claims, characterised in that the aircraft comprises sensors for determining the height (height sensors).

15. Flight system according to Claim 14, characterised in that the height sensors comprise ultrasonic sensors and sensors for determining the air pressure.

16. Flight system according to any one of the preceding claims, characterised in that the aircraft comprises distance sensors on its sides.

17. Flight system according to any one of the preceding claims, characterised in that the flight system comprises a plurality of operating modes.

18. Flight system according to Claim 17, characterised in that the flight directions of the aircraft are specified by the coordinate system of the remote controller in a first operating mode.

19. Flight system according to Claim 17, characterised in that the flight directions of the aircraft are specified by the coordinate system in the aircraft in a second operating mode (First-Person-View-System).

20. Flight system according to any one of the preceding claims, characterised in that the aircraft comprises at least one GPS receiver, which is connected to the data processing means of the aircraft and/or of the remote control.

21. Flight system according to any one of the preceding claims, characterised in that the remote control comprises at least one GPS receiver, which is connected to the data processing means in the remote control. 1968583v1