EXOSKELETAL ARM AID IN THE AIRCRAFT COCKPIT FOR HIGH ACCELERATIONS

Description

[0001] The invention relates to a system for assisting an occupant of an aircraft in cockpit operation under high accelerations, as well as to an aircraft with such a system.

[0002] In manned flight control, a pilot typically has control elements at his disposal to operate subsystems of his aircraft. Such controls affect communication, navigation, lights, and, depending on the aircraft type, other functions. For flight control itself, i.e. to influence an aircraft state with components for moment dynamics (roll, pitch, yaw) and components for translational acceleration and speed, appropriate control elements are available depending on the configuration of the aircraft. In fixed-wing aircraft, such control elements typically include a control stick for controlling pitch and roll movements, as well as one or more thrust levers for setting a desired thrust lever position correlated with a desired thrust of the aircraft's engine(s), and pedals for controlling a moment around the aircraft's vertical axis.

[0003] Specific configurations of manned aircraft often exhibit peculiarities regarding their degrees of freedom in thrust and aerodynamic control surfaces, which can be reflected in the design of the controls in the cockpit of the manned aircraft. While, for example, commercial aircraft are expected to experience moderate acceleration during turns, etc., and therefore large and slow-actuating control horns represent an ergonomic option, agile combat aircraft can achieve accelerations of 9g and more due to the ability to execute tight turns at high speeds.

[0004] The control elements mentioned above are also available in a wide variety, depending on the configuration and type of manned aircraft. While historical aircraft exclusively featured analog instruments (displays) and mechanical switches and buttons, modern aircraft increasingly use digital displays, which can at least partially assume the function of control elements by being designed as touchscreens.

[0005] In all cases, however, it is challenging for the pilot to read instruments correctly and operate controls correctly during flight, as quasi-static and dynamic accelerations such as load factors caused by gusts, vibrations from drives such as rotors, propellers, internal combustion engines and the like make the coordination of the pilot or co-pilot more difficult.

[0006] Particularly in highly agile aircraft such as combat aircraft (interceptors, multi-role combat aircraft, air superiority fighters) or aerobatic aircraft, the pilot is exposed to high accelerations during maneuvers such as, in military jargon, dogfights. These accelerations are not only directed toward the pilot's seat, forcing the pilot into the seat at a rate many times greater than normal gravitational acceleration, but can also be directed away from the pilot's seat due to the aircraft's pitching. High lateral accelerations can also act on the pilot, for example, during rapid build-up or recovery of high roll rates around the aircraft's longitudinal axis, and in rare cases for special configurations, even during a yaw motion.

[0007] Such quasi-static accelerations and vibrations can significantly complicate manual operation of the cockpit for the aforementioned controls and controls, such as the joystick and throttle. Not only do higher-frequency vibrations negatively impact the pilot's hand-eye coordination, but the quasi-static accelerations, which are many times greater than the acceleration due to gravity, also require considerable muscular effort from the pilot to compensate for the inertial force of the arms and hands against the acting acceleration. This places a strain on the pilot and, over extended periods, leads to fatigue. With such high accelerations acting on the pilot's body, voice control is also virtually impossible, as clear speech is also hampered, even making it impossible to pronounce common phrases.While, for these reasons and to minimize the pilot's reaction time when operating the human-machine interface (and therefore without citing a specific document from the state of the art), the state of the art typically uses a cockpit based on the HOTAS principle (HOTAS is an abbreviation for "Hands on Throttle and Stick"), particularly in combat aircraft, touchscreens are increasingly being used due to the high functionality and increasing complexity of military aircraft. Complex control inputs are also difficult to achieve using the HOTAS principle, as buttons and mini-joysticks on the throttle and / or control stick provide too few degrees of freedom, or they lead to cumbersome operation.While anti-G suits for pilots, also commonly used in the military, help maintain blood circulation and thus oxygen supply to tissues and the brain, and thus vital functions, they cannot reduce the inertial forces on the limbs when operating the cockpit. The same applies to the forced breathing frequently used during high acceleration.

[0008] It is therefore an object of the invention to simplify the manual operation of a cockpit of a manned aircraft that is highly agile or otherwise subjected to high accelerations for an occupant, in particular the pilot or the co-pilot.

[0009] US 4 967 985 A discloses an aircraft crew support system for supporting the head and, if applicable, the torso of a pilot during high gravity maneuvers, allowing him to keep his head in an upright position and thereby improving his awareness of the situation outside the cockpit at all times.US 2020 / 231269 A1 discloses a flight arrangement and a glider with bi-directional, flexible and foldable wings and an associated flight procedure.

[0010] The invention results from the features of independent claim 1. Advantageous further developments and embodiments are the subject of the dependent claims.

[0011] A first aspect of the invention relates to a system for assisting an occupant of an aircraft during cockpit operation under high accelerations, comprising a computing unit, an inertial measuring unit, and an exoskeleton arm with a plurality of joints and actuators and bearing surfaces for supporting an arm of the occupant, wherein the inertial measuring unit is designed to record kinematic data of the aircraft and transmit it to the computing unit, wherein the computing unit is designed to determine an acceleration at the pilot's seat from the recorded kinematic data of the inertial measuring unit and to control the actuators of the exoskeleton arm to generate a counterforce opposite to the determined acceleration at the pilot's seat at a height which compensates for the inertial forces of the occupant's arm due to the determined acceleration at the pilot's seat.

[0012] As expected, in most cases the occupant is a pilot. In keeping with the common phrase "pilot flying" and "pilot not flying," the term "pilot" in the above and following refers to both a pilot and a co-pilot, as well as a weapons systems officer. In combat aircraft, it is not uncommon for a two-person crew to be seated one behind the other, and in a few rare cases of combat aircraft and helicopters, side by side.

[0013] The kinematic data of the inertial measurement unit preferably include accelerations and / or rotation rates of the aircraft. Particularly preferably, the kinematic data of the inertial measurement unit include both accelerations and rotation rates of the aircraft, and further particularly preferably both translational and rotational accelerations of the aircraft. This is particularly useful when the inertial measurement unit is arranged in the region of an expected center of gravity of the aircraft, i.e., typically at a distance at least in the longitudinal direction of the aircraft from the pilot's seat.If such an arrangement of the inertial measuring unit is used, on the one hand the stationary load factor of the aircraft in stationary turning flight can be transferred directly to the pilot's seat through the translational acceleration alone (as measured in the inertial measuring unit). However, if a pitching movement is also built up in the aircraft, this translational acceleration measured at the aircraft's center of gravity is not sufficient, since the radius between the inertial measuring unit in or near the aircraft's center of gravity and the pilot's seat represents a radius of a circular movement of the pilot's seat around the aircraft's center of gravity during the aircraft's rotation. By knowing this radius and the rotational movement of the aircraft, the final resulting acceleration at the pilot's seat can be deduced. This is the task of the computing unit.Depending on the attitude angles at which the inertial measurement unit is positioned relative to the rest of the aircraft's structure and its distance from the pilot's seat, different kinematic data are required to determine the resulting acceleration vector at the pilot's seat. Therefore, we generally refer to kinematic data, as the specific kinematic data required to determine the acceleration vector, as determined by all motion states of the aircraft, depends on the respective situation.

[0014] For this purpose, the inertial measurement unit incorporates specific sensors in accordance with the aforementioned requirements, such as gyroscopes for determining orientation (i.e., the aircraft's attitude angle) and angular rates, and corresponding acceleration sensors for determining acceleration. If the inertial measurement unit normally installed in the aircraft is used for flight control purposes and to obtain information about the current flight status for display on cockpit instruments, it is also used for the aforementioned purposes of determining the acceleration vector at the pilot's seat to determine the counterforce for the exoskeleton arm, these types of sensors are typically installed anyway.

[0015] The exoskeleton arm has a plurality of actuators and joints. The joints are preferably modeled in their degrees of freedom and position on those of the occupant's human arm. For example, the exoskeleton arm preferably has a shoulder joint, which, for example, is designed as a ball joint and can be rotated about a point-like bearing point. Furthermore, an elbow joint is preferably provided so that the forearm supported on the exoskeleton arm can also move within the degree of freedom of the elbow, allowing an angle between the upper arm and forearm to be adjusted. This advantageously allows the occupant a natural movement of their human arm, which is accommodated in the exoskeleton arm, in order to operate the aircraft cockpit in the usual way, with only the support of the counterforce generated by the actuators of the exoskeleton arm.This counterforce is preferably of such a nature in direction and magnitude that any additional force otherwise required by the occupant to overcome the inertial force acting on his arm, which is caused by flight maneuvers on curved paths, is compensated in direction and height, and the pilot must either hold the arms in an artificial weightlessness or against the simple acceleration due to gravity.

[0016] The actuators are preferably electric actuators, as they offer the lightest design in terms of controllability and the required torque. To transmit the torque / force of the actuators as a counterforce to the occupant's human arm, bearing surfaces are provided on the exoskeleton arm, forming contact surfaces between the exoskeleton arm and the human arm. Forces can be transmitted via these contact surfaces. These contact surfaces are preferably appropriately padded, yet still stiff enough to transmit forces over a sufficiently wide range.

[0017] Alternatively, hydraulic actuators are preferably used, whereby advantageously no separate hydraulic system is required to generate hydraulic pressure, but the existing hydraulic system of the aircraft can be used.

[0018] The exoskeleton arm is therefore preferably placed around the occupant's human arm, and its geometric shape therefore preferably follows the dimensions of the human arm. While, in principle, a single exoskeleton arm with the described function can be installed in an aircraft to support the occupant's human arm during high aircraft accelerations, such as during fast turns, two exoskeleton arms are preferably provided per pilot, allowing the pilot to operate the cockpit with both arms.

[0019] An advantageous effect of the invention is that the resulting less fatigued operation and control of an aircraft can increase the so-called "situational awareness" and reduce the reaction time of the aircraft occupant. Fatigue caused by extreme physical exertion during increased acceleration, particularly of a quasi-static nature, can be reduced, thus increasing performance and the ability to concentrate on the situation. By using an actively supporting exoskeleton for the shoulder, upper arms, and / or forearms or hand, the pilot has to exert less physical exertion, thus reducing pilot fatigue. The system can also be used for spacecraft launched from Earth.The spacecraft are not aircraft in the strict sense, but should be considered as such within this document, since they can also have high accelerations and fly through the Earth's atmosphere during takeoff or for landing on Earth after re-entering it.

[0020] According to an advantageous embodiment, an inertial arm measuring unit is arranged on the exoskeleton arm and is designed to determine kinematic data of the exoskeleton arm and to transmit it to the computing unit, wherein the computing unit is designed to determine the counterforce from the kinematic data of the aircraft recorded by means of the inertial measuring unit and from the kinematic data of the exoskeleton arm recorded by means of the inertial arm measuring unit and to control the actuators of the exoskeleton arm to apply the determined counterforce.

[0021] According to this embodiment, both the aircraft's inertial measurement unit for determining aircraft-related kinematic data and the inertial arm measurement unit for determining exoskeleton-related kinematic data are used jointly to determine the magnitude and direction of the counterforce. Preferably, the calculation of the acceleration at the pilot's seat using the aircraft's inertial measurement unit serves as a feedforward signal for the counterforce, while the actually measured acceleration by the inertial arm measurement unit can be used for corrections and a control loop to correct and refine the feedforward control.

[0022] Preferably, a first inertial arm measuring unit is arranged in the area of ​​the human upper arm for each exoskeleton arm, and a second inertial arm measuring unit is arranged in the area of ​​the human forearm for each exoskeleton arm. Again, analogous to the inertial measuring unit of the aircraft, the kinematic data of the inertial arm measuring unit preferably relate to accelerations, in particular translational accelerations. Angular rates are not necessary when measuring translational accelerations directly at one or more inertial arm measuring units if sufficient information about locally occurring translational accelerations is available.

[0023] According to a further advantageous embodiment, the exoskeleton arm has bio-sensors which are designed to determine action potentials of the occupant and to transmit them to the computing unit, wherein the computing unit is designed to determine a movement of the exoskeleton arm desired by the occupant on the basis of the action potentials determined by the bio-sensors and to control the actuators superimposed on the counterforce to apply a force and / or a moment to execute the desired movement of the exoskeleton arm.

[0024] These biosensors are specifically designed to detect the occupant's desired movement at the very beginning of the movement and, with the help of the actuators, to support the movement in such a way that the exoskeleton arm is moved along and thus practically unnoticeable to the occupant. The necessary force or torque from the actuators is then applied superimposed on the detected counterforce.

[0025] According to a further advantageous embodiment, the computing unit is designed to determine a spatial direction of the acceleration occurring at the pilot's seat and to determine the counterforce along this direction and to control the actuators of the exoskeleton arm accordingly. By determining the acceleration as a spatial vector with three components of a Cartesian coordinate system, it is possible to determine and apply a counterforce with a spatial orientation. Although this increases the complexity of the necessary designs of the actuators and joints of the exoskeleton arm, it allows for fully supported movement of the human pilot's arm.

[0026] According to a further advantageous embodiment, the system further comprises an optical tracking system which is designed to detect a current position and / or speed of the exoskeleton arm relative to the cockpit and to transmit it to the computing unit, wherein the computing unit is designed to adjust a movement of the exoskeleton arm and / or the counterforce on the basis of the determined position and / or speed of the exoskeleton arm.

[0027] According to a further advantageous embodiment, the inertial measuring unit is provided for arrangement in the aircraft at a distance from the pilot's seat along a longitudinal axis of the aircraft, wherein the computing unit is designed to calculate the accelerations at the pilot's seat using the known distance and the kinematic data of the inertial measuring unit. This component of the final resulting acceleration at the pilot's seat is determined in particular from the pitch rate of the aircraft and from the lever arm between the pilot's seat and the center of gravity of the aircraft, and further preferably from the derivative of the pitch rate of the aircraft. Superimposed on this component, the translational accelerations due, for example, to cornering, as well as other accelerations such as those due to a changed rolling motion of the aircraft must also be taken into account.

[0028] According to a further advantageous embodiment, the exoskeleton arm has respective bearing surfaces for an upper arm and a forearm adjoining the upper arm.

[0029] According to a further advantageous embodiment, the exoskeleton arm has joints with degrees of freedom that are designed analogously to the degrees of freedom of the human shoulder and the human elbow, so that for the arm of the occupant accommodated in the exoskeleton arm, all movements possible due to its degrees of freedom in the shoulder and elbow are also possible through the exoskeleton arm and are supported by the actuators of the exoskeleton arm against the determined acceleration by the counterforce.

[0030] A further aspect of the invention relates to an aircraft having a system as described above and below.

[0031] According to a further advantageous embodiment, the aircraft has a first and a second exoskeleton arm, wherein the respective exoskeleton arm is mounted on the aircraft structure at shoulder height behind the passenger seat backrest.

[0032] Advantages and preferred developments of the proposed aircraft result from an analogous and analogous transfer of the statements made above in connection with the proposed system.

[0033] Further advantages, features, and details will become apparent from the following description, in which at least one embodiment is described in detail—possibly with reference to the drawings. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0034] They show: Fig. 1: A system for assisting a pilot of an aircraft in cockpit operation under high accelerations according to an embodiment of the invention. Fig. 2: An aircraft with a system according to Fig. 1 according to an embodiment of the invention.

[0035] The representations in the figures are schematic and not to scale.

[0036] Fig. 1 shows a system for assisting a pilot of a single-seat combat aircraft 1 in cockpit operation under high acceleration. Shown is a cockpit of the aircraft 1 of the Fig. 2 with main flight direction to the top left in the plane of the Fig. 1 , with the windshield and an instrument panel indicated. Further down on the right in the drawing, the pilot's seat is shown. The system for supporting the pilot has the following: a computing unit 3, an inertial measuring unit 5, and a first and second exoskeleton arm 7, each with a plurality of joints and actuators and bearing surfaces for supporting a respective arm of the pilot. The inertial measuring unit 5 is firmly connected to the aircraft structure and serves to determine translational and rotational accelerations, attitude angles, and body-fixed rotation rates of the aircraft 1, each with reference to a point as close as possible to its center of gravity (the center of gravity of the aircraft 1 fundamentally changes depending on refueling and loading).This kinematic data of the aircraft 1 is transmitted to the computing unit 3, which in turn serves to determine an acceleration at the pilot's seat from the recorded kinematic data of the aircraft-mounted inertial measurement unit 5, to determine a counterforce dependent on the arm mass of the respective pilot's arm from this acceleration, and to control the actuators of the exoskeleton arm 7 to generate a counterforce opposite to the determined acceleration at the pilot's seat at a height that compensates for the inertial forces of the pilot's arm due to the determined acceleration at the pilot's seat. The mass of the respective pilot's arm can be preset, but preferably adjusted during flight using a mass estimator. A correspondingly rapid convergence of the mass estimator algorithm is assumed.This can be done by measuring gravity on the ground or dynamically during flight using the kinematic data from the inertial measurement unit 5. Alternatively, the inertial arm measurement units located on each exoskeleton arm 7 are used to adjust accordingly to compensate for unwanted acceleration due to disturbances. These inertial arm measurement units are located on the respective exoskeleton arm 7 and serve to determine kinematic data in the form of absolute translational accelerations of the exoskeleton arm 7 and transmit them to the computing unit 3.The respective exoskeleton arm 7 is mounted on the aircraft structure at shoulder height behind the pilot and has shoulder joints and elbow joints to represent degrees of freedom, which are designed analogously to the degrees of freedom of the human shoulder and the human elbow, so that the arm of the pilot accommodated in the exoskeleton arm 7 can also perform all movements possible due to its degrees of freedom in the shoulder and elbow through the exoskeleton arm 7 and is supported by the actuators of the exoskeleton arm 7 against the determined acceleration by the counterforce.

[0037] Fig. 2 shows the aircraft 1 with the system after Fig. 1 from an upper view.

[0038] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that numerous variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims. List of reference symbols

[0039] 1Aircraft 3Computing unit 5inertial measuring unit 7Exoskeleton arm

Claims

1. A system to assist an occupant of an aircraft during cockpit operation under high accelerations, wherein the system comprises: an exoskeleton arm comprising a plurality of joints, actuators, and bearing surfaces to support an arm of the occupant; an inertial measuring unit configured to detect kinematic data of the aircraft and to transmit the kinematic data; and a computing unit configured to: receive the kinematic data transmitted from the inertial measuring unit; determine an acceleration at the occupant's seat from the kinematic data; and control the actuators of the exoskeleton arm to generate a counterforce directed against the acceleration at the occupant's seat in an amount that compensates for inertial forces of the occupant's arm due to the acceleration at the occupant's seat.

2. The system according to claim 1, wherein the system further comprises an inertial arm measuring unit arranged on the exoskeleton arm, the inertial arm measuring unit configured to determine kinematic data of the exoskeleton arm and transmit the kinematic data of the exoskeleton arm to the computing unit, the computing unit being further configured to determine the counterforce from the kinematic data of the aircraft detected by the inertial measuring unit and from the kinematic data of the exoskeleton arm determined by the inertial arm measuring unit, and to control the actuators of the exoskeleton arm in order to apply the counterforce as determined.

3. The system according to claim 1, wherein the exoskeleton arm comprises bio-sensors configured to determine action potentials of the occupant and transmit the action potentials to the computing unit, the computing unit being further configured to determine a movement of the exoskeleton arm desired by the occupant based on the action potentials determined by the bio-sensors, and to control the actuators superimposed on the counterforce in order to apply a force and / or a torque to carry out the movement of the exoskeleton arm desired by the occupant.

4. The system according to claim 1, wherein the computing unit is further configured to determine a spatial direction of the acceleration occurring at the occupants seat, to determine the counterforce along the spatial direction, and to control the actuators of the exoskeleton arm accordingly.

5. The system according to claim 1, wherein the system further comprises an optical tracking system configured to detect a current position and / or a current speed of the exoskeleton arm relative to the cockpit of the aircraft, and to transmit the current position and / or the current speed to the computing unit, the computing unit being further configured to readjust a movement of the exoskeleton arm and / or the counterforce based on the current position and / or the current speed of the exoskeleton arm.

6. The system according to claim 1, wherein the inertial measuring unit is intended to be arranged in the aircraft at a known distance from the occupant's seat along a longitudinal axis of the aircraft, the computing unit being further configured to calculate accelerations at the occupant's seat using the known distance and from the kinematic data of the inertial measuring unit.

7. The system according to claim 1, wherein the exoskeleton arm further comprises respective bearing surfaces for an upper arm and a forearm adjoining the upper arm.

8. The system according to claim 7, wherein the joints of the exoskeleton arm have degrees of freedom configured analogously to degrees of freedom of a human shoulder and a human elbow, such that the occupant's arm accommodated in the exoskeleton arm is capable of performing all movements possible due to its degrees of freedom in the shoulder and the elbow through the exoskeleton arm as well, and the actuators of the exoskeleton arm support all the movements by the counterforce against the acceleration as determined.

9. An aircraft comprising a system according to claim 1.

10. The aircraft according to claim 9, wherein the aircraft comprises a first exoskeleton arm and a second exoskeleton arm, wherein respective exoskeleton arms are mounted on structure of the aircraft structure at shoulder height behind the occupant's seat.