Extravehicular manned mobile device and autonomous driving method

Abstract

The application discloses an autonomous driving method of an extravehicular manned mobile device, which comprises the following steps: S1, determining a rendezvous target and a rendezvous time, calculating a required speed increment with time as a constraint, and then driving a thruster of the extravehicular manned mobile device to realize movement; S2, after the extravehicular manned mobile device driven in S1 approaches the rendezvous target, the extravehicular manned mobile device is decelerated and relatively stationary; and S3, the extravehicular manned mobile device is again slowly approached to the rendezvous target until the rendezvous target is reached. The application has the automatic driving function, is convenient for astronauts to reach the predetermined area, and can automatically keep the extravehicular manned mobile device during the operation of the astronauts, thus liberating the hands of the astronauts and providing a stable attitude. The application has the anti-collision and propellant shortage alarm functions, and the extravehicular manned mobile device can automatically return under the condition that the astronauts are in a coma or lose the operation function, thus increasing the safety of the extravehicular activity of the astronauts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of space devices, and particularly relates to an extravehicular manned mobile device and an autonomous driving method. BACKGROUND

[0002] The extravehicular manned mobile device can be used by astronauts to realize extravehicular walking, maintenance and repair, and service upgrade, thereby expanding the space activity and working capacity of astronauts. At present, the extravehicular manned mobile device needs to be controlled by astronauts throughout the whole process, which is heavy on the operation of astronauts, has certain safety risks, and cannot free the hands of astronauts during walking. SUMMARY

[0003] The technical purpose of the present application is to provide an extravehicular manned mobile device and an autonomous driving method, so as to improve the extravehicular working capacity of astronauts.

[0004] To solve the above problems, the technical scheme of the present application is as follows:

[0005] An autonomous driving method of an extravehicular manned mobile device, comprising the following steps:

[0006] S1: determining a rendezvous target and a rendezvous time, calculating a required speed increment with time as a constraint, and driving a thruster of the extravehicular manned mobile device to realize movement;

[0007] S2: slowing down and being relatively stationary after the extravehicular manned mobile device driven to approach the rendezvous target;

[0008] S3: approaching the rendezvous target at a low speed again until reaching the rendezvous target.

[0009] In step S1, the required speed increment is calculated with time as a constraint, and specifically:

[0010] According to the rendezvous time, a two-pulse guidance is used to calculate the required speed increment, and a relative position vector p and a relative velocity vector q of the current position and the rendezvous target position are defined;

[0011]

[0012] A state transition equation of a two-pulse orbit is constructed, and the required working time of the thruster is calculated according to the current position and the rendezvous target position, and the calculation formula is

[0013]

[0014] Wherein, t0 is an initial time, τ is a rendezvous time, t is a termination time, A(τ), B(τ), C(τ), D(τ) are transition matrices, and Δu0 is a required speed increment.

[0015] Specifically, the calculation formula of the transition matrix is:

[0016]

[0017]

[0018]

[0019]

[0020] wherein, Ω is the projection of the angular velocity of the space station orbit coordinate system relative to the inertial system in the orbit coordinate system, satisfying the following formula:

[0021] Ω = (0, -Ω, 0) T .

[0022] Further preferably, in step S2, the real-time relative speed of the driving extravehicular manned mobile device to the rendezvous target is also included as a feedback quantity to maintain the hovering state close to the rendezvous target.

[0023] Further preferably, in step S3, the real-time relative position and relative speed of the driving extravehicular manned mobile device to the rendezvous target are also included as feedback quantities to approach the rendezvous target at low speed.

[0024] Further preferably, a collision avoidance warning is further included, and the calculation formula is

[0025]

[0026] wherein, r = [r x r y r z ] T is the projection of the position of the astronaut relative to the space station in the space station orbit coordinate system, v = [v x v y v z ] T is the projection of the relative speed, F is the thrust of the thruster, R s is the safety radius, t τ is the reaction time, m0 is the total mass of the astronaut and the extravehicular manned mobile device; when the left side of the formula is less than the safety radius R s , it is determined that a collision with the rendezvous target will occur, and a warning information is issued to prompt deceleration.

[0027] An extravehicular manned mobile device applying the autonomous driving method of the extravehicular manned mobile device as described above, comprising a sensitive component assembly, a main control module and a power module;

[0028] The sensitive component assembly is used to measure the current position, speed of the extravehicular manned mobile device, and the position, speed and attitude information relative to the rendezvous target;

[0029] The main control module is used for receiving information measured from the sensitive element assembly and external remote control instructions to generate corresponding control logic, and driving the power module based on the control logic to drive the extravehicular manned machine.

[0030] Specifically, the sensitive element assembly includes differential GNSS, microwave measuring instrument, micro-inertial unit, gyroscope, magnetometer, navigation camera and star sensor.

[0031] The differential GNSS cooperates with the micro-inertial unit to measure the relative navigation information of the extravehicular manned machine and the rendezvous target.

[0032] The microwave measuring instrument is used for measuring relative position information.

[0033] The navigation camera is used for measuring relative position and attitude information.

[0034] The gyroscope is used for measuring direction and angle information.

[0035] The magnetometer is used for measuring the component of the geomagnetic field strength vector in the local system.

[0036] The star sensor is used for measuring the current attitude information.

[0037] The main control module includes a logic control device and a servo mechanism and driving circuit.

[0038] The logic control device receives information measured from the sensitive element assembly and external remote control instructions to generate corresponding control logic, and the servo mechanism and driving circuit are used for receiving the control logic to drive the power module to drive the extravehicular manned machine.

[0039] Further preferably, it further comprises a manual control interface unit, a translation handle and an attitude control handle.

[0040] The input end of the manual control interface unit is respectively connected with the translation handle and the attitude control handle, and the output end of the manual control interface unit is connected with the logic control device, which is used for generating corresponding translation and attitude transformation control signals and inputting the control signals to the logic control device through the manual control interface unit, thereby supporting manual translation control and attitude transformation control.

[0041] The present application has the following advantages and positive effects compared with the prior art due to the adoption of the above technical scheme:

[0042] (1) It has an automatic driving function, which is convenient for astronauts to reach the predetermined area.

[0043] (2) During the operation of the astronauts, the extravehicular manned machine is automatically maintained, which can free the hands of the astronauts and provide a stable attitude.

[0044] (3) The device has anti-collision and insufficient propellant warning functions, and can automatically return to the space station under the condition that the astronaut is in a coma or loses the operating function, thus increasing the safety of the astronaut's extravehicular activity. BRIEF DESCRIPTION OF DRAWINGS

[0045] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limiting of the application to what is illustrated in the drawings.

[0046] Figure 1 The autonomous driving method of the extravehicular manned mobile device provided by the application;

[0047] Figure 2 The structural block diagram of the extravehicular manned mobile device provided by the application;

[0048] Figure 3 The external structure diagram of the extravehicular manned mobile device provided by the application;

[0049] Figure 4 The extravehicular orbiting curve diagram of the extravehicular manned mobile device provided by the application;

[0050] Figure 5 The astronaut and space station rendezvous curve diagram provided by the application;

[0051] Figure 6 The insufficient propellant warning diagram provided by the application;

[0052] Figure 7 The anti-collision warning curve diagram provided by the application. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, specific implementation manners of the application will be described below with reference to the drawings. Obviously, the drawings in the following description only represent some embodiments of the application, and for those of ordinary skill in the art, other drawings can be obtained from these drawings without creative effort, and other embodiments can also be obtained.

[0054] In order to make the drawings simple, only the parts related to the application are shown in the drawings, and they do not represent the actual structure of the product. In addition, in order to make the drawings simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown, or only one of them is marked. In this article, "one" not only means "only one", but also means "more than one".

[0055] The application will be further described in detail below in connection with the accompanying drawings and specific embodiments. The advantages and features of the application will be more apparent from the following description and claims.

[0056] Embodiment 1

[0057] Referring to Figure 1 , the embodiment provides an autonomous driving method of an extravehicular manned mobile device, which is applied to an extravehicular manned mobile device worn by an astronaut, and can realize the function of autonomous driving. When the astronaut performs a task outside the spacecraft, the astronaut needs to drive to a specific target position, approach a target satellite or return to the space station. The automatic control mode is realized by relying on the navigation information of the astronaut, the control system calculates the required orbit, and drives the actuator to work. The astronaut only needs to select the target position, plan the time and supervise the MMU (extravehicular manned mobile device) during the whole process. The automatic control mode can reduce the operation difficulty of the astronaut, save fuel and time, but the flexibility of the task is low. In the manual control mode, the astronaut only needs to observe visually and manually operate the drive MMU to drive to the target position, and the control system assists to keep the astronaut's posture stable. The astronaut needs to be trained on the ground in the manual control mode, and the operation difficulty is large. Compared with the automatic control mode, the manual control will consume more fuel and time, but this mode has high flexibility, small dependence on navigation equipment and high reliability, and is the main way for the astronaut to move at the present stage.

[0058] And the automatic mode of the extravehicular manned mobile device driving to the rendezvous target includes the following steps:

[0059] Referring to Figure 4 and Figure 5 , the extravehicular flight curve is shown. First, the embodiment determines the rendezvous target and the rendezvous time, calculates the required velocity increment with time as the constraint, and then drives the thruster of the extravehicular manned mobile device to move, specifically:

[0060] According to the rendezvous time, the required velocity increment is calculated by two-pulse guidance, and the relative position vector p and the relative velocity vector q of the current position and the rendezvous target position are defined.

[0061]

[0062] The state transition equation of the two-pulse orbit is constructed, and the required working time of the thruster can be calculated according to the current position and the rendezvous target position, and the calculation formula is

[0063]

[0064] Where t0 is the initial time, τ is the rendezvous time, t is the termination time, A(τ), B(τ), C(τ), D(τ) are the transition matrix, and Δu0 is the required velocity increment.

[0065] The transition matrix in the state transition equation is calculated by the following formula:

[0066]

[0067]

[0068]

[0069]

[0070] Where Ω is the projection of the angular velocity of the space station orbit coordinate system relative to the inertial system in the orbit coordinate system, satisfying the following formula:

[0071] Ω = (0, -Ω, 0) T .

[0072] Therefore, the transition matrix is brought into the state transition equation to solve the required velocity increment Δu0, and then the thruster working time is calculated according to the velocity increment.

[0073] Next, the extravehicular manned mobility device to be driven is slowed down and relatively stationary after approaching the rendezvous target, and the real-time relative velocity of the extravehicular manned mobility device to be driven and the rendezvous target is taken as a feedback quantity during this process, and a hovering state is maintained when the rendezvous target is in close proximity.

[0074] Then, the extravehicular manned mobility device to be driven is slowly approached to the rendezvous target until it reaches the rendezvous target, and the real-time relative position and relative velocity of the extravehicular manned mobility device to be driven and the rendezvous target are taken as feedback quantities to slowly approach the rendezvous target during this process.

[0075] As shown in the formula: Figure 7 The embodiment also has a collision avoidance warning mechanism, and the calculation formula is

[0076]

[0077] Where r = [r x r y r z ] T is the projection of the position of the astronaut relative to the space station in the space station orbit coordinate system, v = [v x v y v z ] T is the projection of the relative velocity, F is the thrust of the thruster, R s is the safety radius, t τ is the reaction time, and m0 is the total mass of the astronaut and the extravehicular manned mobility device. When the left side of the formula is less than the safety radius R sWhen the determination is made that a collision with the rendezvous target (space station) will occur, a warning message is sent to the astronauts, prompting them to brake and slow down.

[0078] Embodiment 2

[0079] Referring to Figure 2 and Figure 3 This embodiment provides an extravehicular manned mobile device, which applies the autonomous driving method of the extravehicular manned mobile device as in Embodiment 1.

[0080] The design of this embodiment has the following points:

[0081] First, the structure of this embodiment is lightweight, and the electronic components are small and integrated, with the overall mass designed to be 100 kg. Figure 3 As shown in the figure, the design of the outer shape of this embodiment mainly considers ergonomics, taking the body shape and operation mode of the astronauts as the design basis, and at the same time, the structure and shape provide support for other subsystems. The diameter of the space station hatch is also taken into account in the design constraints, and the embodiment can pass through a hatch with a diameter of 1 m in the retracted state.

[0082] This embodiment also involves the design of the speed increment: Since the astronauts need to approach, hover, fly around, orient, and de-spin during extravehicular maintenance or observation, taking the maintenance of a spacecraft 100 m away from the space station as a typical task, the specific process is as follows: After the astronaut exits the spacecraft, he moves to the target area, hovers and flies around for observation, then contacts the target for maintenance, and returns to the space station after the task is completed. Preliminary estimates show that the speed increment consumed by approaching, flying around, and hovering is about 10 m / s. During the entire task, the attitude control and orbit control consume a considerable amount of propellant, so the estimated speed increment consumed by attitude control is 10 m / s, and 25% of the total propellant is taken as a safety margin for safety considerations. Considering the size of the envelope and the volume limitation of the gas cylinder, the preliminary estimate of the speed increment is 30 m / s.

[0083] In addition, this embodiment also involves the design of control accuracy: Control accuracy includes attitude and orbit accuracy, and the factors considered in parameter setting include navigation accuracy, control ability of the propulsion system, precision requirements of the robotic arm capture, and fuel consumption, etc. First, the control ability of this embodiment must meet the precision requirements of the robotic arm capture and the requirements of the load on the platform, and at the same time, the control accuracy of this embodiment is also constrained by the measurement accuracy of the navigation equipment and the execution ability of the cold gas propulsion system.

[0084] The extravehicular working time of the embodiment is designed as follows: the main factors affecting the extravehicular working time of the astronauts are the endurance of the astronauts, the supply capacity of the life support system, the propellant carried by the platform and the capacity of the storage battery carried by the platform. The endurance of the astronauts is the most important factor. Under the condition of no sufficient supply and no rest, long working time will cause the astronauts to be tired and even dangerous. Meanwhile, considering the limited propellant and the capacity of the storage battery under the condition of the small spacecraft operated by a single astronaut, the longest extravehicular working time of the astronauts using the embodiment is preliminarily designed as 6 hours.

[0085] Referring to Figure 2 , the interior of the embodiment will now be described: including the sensitive element assembly, the main control module and the power module.

[0086] The sensitive element assembly is mainly used for measuring the current position, speed of the extravehicular manned spacecraft and the position, speed and attitude information relative to the target of the rendezvous. It is subdivided into differential GNSS, microwave measuring instrument, micro-inertial group, gyroscope, magnetometer, navigation camera and star sensor. The differential GNSS cooperates with the micro-inertial group to measure the relative navigation information of the extravehicular manned spacecraft and the target of the rendezvous. The microwave measuring instrument is used to measure the relative position information. The navigation camera is used to measure the relative position and attitude information. The gyroscope is used to measure the direction and angle information. The magnetometer is used to measure the component of the geomagnetic field strength vector in the system. The star sensor is used to measure the current attitude information.

[0087] The main control module includes a logic control device and a servo mechanism and driving circuit. The logic control device receives the information measured from the sensitive element assembly and the external remote control instructions to generate corresponding control logic instructions, and the servo mechanism and driving circuit are used to receive the control logic instructions to drive the power module to drive the extravehicular manned spacecraft.

[0088] Preferably, the embodiment also has a manual control interface unit, a translation handle and an attitude control handle. The input end of the manual control interface unit is respectively connected with the translation handle and the attitude control handle, the output end of the manual control interface unit is connected with the logic control device, and the manual control interface unit is used to generate corresponding translation and attitude transformation control signals and input to the logic control device, thereby supporting the manual translation control and attitude transformation control of the astronauts.

[0089] The above-mentioned power module is a thruster, which is designed as follows: since the thrust needs to meet the requirements of the embodiment for realizing the space rendezvous, attitude orientation, hovering and circling, etc., generally speaking, the circling requires the highest thrust of the spacecraft. Taking the circling radius as 100m and the circling time as 10 minutes for calculation, the circling thrust is at least 7N, and two engines are provided, each of which is at least 3.5N. In order to ensure the accuracy of the operation of the astronauts, the thrust should not be too large, and the thruster with a thrust of 5N is selected in combination with the existing type.

[0090] The real-time process of the present embodiment is briefly illustrated as follows: when the space station is orbiting forward in a positive flight attitude, the space station manipulator arm actively captures, docks and returns the present embodiment, and the MMU hovers at a distance of 2 m from the space station hatch. In the mode of capturing the MMU by the manipulator arm, the hovering position control accuracy is required to be 0.1 m, the speed control accuracy is required to be better than 0.01 m / s, the attitude control accuracy is required to be better than 1°, and the angular velocity control accuracy is required to be better than 0.2° / s. When the astronauts are in close-range flight, they can rely on the combined measurement mode of differential GNSS and micro inertial components to control the relative position, when the astronauts are in ultra-close-range control, including returning and extravehicular maintenance, the relative position and attitude of the target need to be measured by a navigation camera, the relative distance is measured by a microwave measuring instrument, the close-range relative navigation is established, and the closed-loop control is performed by cold gas propulsion. The astronauts can supervise and take necessary correction or supplementary operation by handle control in the process. As a cooperative target, the air-to-air communication is established between the MMU and the space station, and the relative motion relationship between the two targets can be established.

[0091] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments. Even if various changes are made to the present application, if the changes fall within the scope of the claims of the present application and equivalent technologies thereof, they still fall within the protection scope of the present application.

Claims

1. An autonomous driving method for an extravehicular manned mobility device, characterized in that, Includes the following steps: S1: Determine the rendezvous target and rendezvous time, calculate the required speed increment with time as a constraint, and then drive the thrusters of the extravehicular manned maneuvering device to move. S2: After the manned maneuvering device outside the drive cabin approaches the rendezvous target, it decelerates and comes to a relative stop; S3: Approach the rendezvous target at a low speed until reaching the rendezvous target; Specifically, in step S1, calculating the required velocity increment with time as a constraint involves: Based on the rendezvous time, the required velocity increment is calculated using two-pulse guidance, and the relative position vector between the current position and the rendezvous target position is defined. and relative velocity vector ; ； The state transition equations for the dual-pulse trajectory are constructed, and the required operating time of the thruster is calculated based on the current position and the rendezvous target position. The calculation formula is as follows: in, At the initial moment, The meeting time is... The termination time, , , , Let be the transition matrix. The required speed increment.

2. The autonomous driving method for the extravehicular manned mobility device according to claim 1, characterized in that, The formula for calculating the transition matrix is: in, Let be the projection of the angular velocity of the space station's orbital coordinate system relative to the inertial frame onto the orbital coordinate system, satisfying the following formula: 。 3. The autonomous driving method for the extravehicular manned mobility device according to claim 1, characterized in that, In step S2, the real-time relative speed between the manned maneuvering device outside the drive cabin and the rendezvous target is used as a feedback quantity to maintain a hovering state at close range with the rendezvous target.

4. The autonomous driving method for the extravehicular manned mobility device according to claim 1, characterized in that, In step S3, the real-time relative position and relative speed between the manned maneuvering device outside the drive cabin and the rendezvous target are used as feedback quantities to approach the rendezvous target at low speed.

5. The autonomous driving method for the extravehicular manned mobility device according to claim 1, characterized in that, It also includes collision avoidance warning, the calculation formula of which is: in, This represents the projection of the astronauts' position relative to the space station onto the space station's orbital coordinate system. The projection of relative velocity. For the thrust of the thruster, For the safety radius, For reaction time, The total mass of the astronaut and the extravehicular manned mobility device; when the left side of the formula is less than the safe radius. If a collision is detected with the target object, a warning message will be issued to prompt braking and deceleration.

6. An extravehicular manned mobility device, employing the autonomous driving method of the extravehicular manned mobility device as described in any one of claims 1 to 5, characterized in that, Includes sensitive gas sensor components, main control module, and power module; The sensitive gas sensor assembly is used to measure the current position, speed, and position, speed, and attitude information of the extravehicular manned maneuvering device relative to the rendezvous target; The main control module is used to receive information measured from the sensitive gas generator component and external remote control commands to generate corresponding control logic, and drive the power module based on the control logic to drive the extravehicular manned mobility device.

7. The extravehicular manned mobility device according to claim 6, characterized in that, The sensitive gas sensor assembly includes differential GNSS, microwave measuring instrument, micro inertial navigation system, gyroscope, magnetometer, navigation camera and star sensor; The differential GNSS, in conjunction with the micro inertial navigation system, measures the relative navigation information between the extravehicular manned maneuvering device and the rendezvous target; The microwave measuring instrument is used to measure relative position information; The navigation camera is used to measure relative position and attitude information; The gyroscope is used to measure direction and angle information; The magnetometer is used to measure the component of the geomagnetic field intensity vector at its location within the system. The star sensor is used to measure the current attitude information.

8. The extravehicular manned mobility device according to claim 6, characterized in that, The main control module includes a logic control device and a servo mechanism and drive circuit. The logic control device receives information measured from the sensitive gas generator assembly and external remote control commands to generate corresponding control logic. The servo mechanism and drive circuit are used to receive the control logic to drive the power module to drive the extravehicular manned mobility device.

9. The extravehicular manned mobility device according to claim 8, characterized in that, It also includes a hand control interface unit, a translation handle, and a posture control handle; The input terminals of the hand control interface unit are respectively connected to the translation handle and the attitude control handle, and the output terminals of the hand control interface unit are connected to the logic control device. The hand control interface unit is used to generate corresponding translation and attitude change control signals and input them to the logic control device through the hand control interface unit, thereby supporting manual translation control and attitude change control.

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