Space station robot propelling system based on adjustable aperture nozzle

Abstract

The invention discloses a space station robot propelling system based on an adjustable aperture nozzle. The space station robot propelling system comprises a centrifugal fan air suction pressurization system, an internal curved surface flow guide system and an outlet air injection regulation and control system. Wherein the centrifugal fan air suction pressurization system can finish air suction pressurization through a centrifugal fan, and the centrifugal fan air suction pressurization system serves as a thrust source; the internal curved surface flow guide system comprises arc-shaped wall surfaces connected with the shell, is installed on the two sides of the opposite angles of the shell and can achieve flow guide and store equipment such as a steering engine, the aerodynamic configuration is prevented from being damaged, and the space utilization rate is increased. The outlet air injection systems are installed at the two corners outside the arc-shaped wall face, and precise adjustment of thrust is achieved through adjustable aperture nozzles. The jet-propelled propelling system is improved and designed for solving the problems that an existing space station robot is not high in propelling efficiency and not enough in adjusting precision, and the jet-propelled propelling system based on the adjustable aperture nozzle can effectively meet the advancing and steering requirements and the posture adjusting requirements of the space station robot.

Description

Technical Field

[0001] The present invention relates to the technical field of space station equipment, and more specifically to a space station robot propulsion system based on an adjustable aperture nozzle. Background Art

[0002] The in-space-station cabin robot is a special robot used to perform various tasks in the space station cabin. It can assist astronauts in moving and taking pictures in the space station, inspecting the cabin, managing supplies, inspecting products, etc. It is small in size, light in weight, and highly intelligent. It can work stably in special space environments with microgravity, high vacuum, ultra-low temperature, strong radiation, and poor lighting. In recent years, significant progress has been made in intelligent devices and robot technologies. In the research of related projects of the International Space Station, the research of in-space-station cabin robots has become a major focus, and many countries participating in the International Space Station have invested a large amount of research.

[0003] Existing in-space-station cabin robots mostly use jet propulsion for motion and attitude control. For example, the next-generation in-space-station cabin robot platform Astrobee developed by NASA uses two symmetric propulsion modules. Each module contains a centrifugal fan and 6 nozzles whose opening and closing sizes can be adjusted. The fan sucks in air to increase the pressure and then expels it through the nozzles for propulsion. Its advantage is sufficient thrust, but the centrifugal fan makes thrust regulation difficult. The insufficient number of nozzles and the lack of sensitivity in adjusting the opening and closing sizes will affect the sensitivity of motion and attitude regulation; the first zero-gravity space environment camera drone Int-ball developed by JAXA (Japan Aerospace Exploration Agency) uses multiple micro fans for propulsion and three flywheels for attitude control. The design of the fan and flywheel can make motion and attitude adjustment more flexible. However, due to the small thrust of the satellite fan, the propulsion efficiency is low, and the flywheel will occupy extra space, restricting the functions of the robot and making it impossible to install relatively large devices such as robotic arms.

[0004] In view of the characteristics of the internal environment of the space station, the present invention innovatively adopts a centrifugal air flow pressurization system in cooperation with an adjustable nozzle structure to achieve precise regulation of the propulsion force. This propulsion system generates negative pressure by a centrifugal fan to suck in gas, which is discharged through an adjustable aperture nozzle after pressurization. It not only meets the basic requirements of the in-space-station cabin robot for propulsion force, but its unique nozzle adjustment mechanism endows the thrust output with high controllability. This design enables the robot to achieve multi-degree-of-freedom motion in the complex cabin environment of the space station, including precise attitude adjustment and flexible displacement control, effectively solving the problem of insufficient adaptability of traditional propulsion methods in enclosed spaces. Summary of the Invention

[0005] Aiming at the low propulsion efficiency and insufficient adjustment precision of the current space station robot, the present invention improves and designs a jet propulsion system based on an adjustable aperture nozzle, which can effectively meet the needs of the space station robot for moving forward, turning and posture adjustment.

[0006] The present invention proposes a space station robot propulsion system based on an adjustable aperture nozzle, comprising a centrifugal fan air intake and pressurization system, an internal curved surface guide system and an outlet jet system; wherein, the main components of the centrifugal fan air intake and pressurization system include a centrifugal fan 1; the main components of the internal curved surface guide system include an arc-shaped wall surface 2 connected to the outer shell; the main components of the outlet jet system include a servo steering gear 3, a transmission shaft 4, a type I gear 5, a type II gear 6 and an adjustable aperture nozzle 7.

[0007] The overall shell of the centrifugal fan air intake and boost system is composed of two rectangular shells on the left and right and the middle main frame, which are fixed with bolts and nuts. The shape after splicing is approximately a cube. The rectangular shell and the main frame are made of resin by 3D printing. A storage platform is installed on the upper, middle and lower sides of the main frame for placing instruments. Two centrifugal fans are installed on the opposite sides of the cube, facing the center. A circular air inlet is opened on the side of the cube, and the centrifugal fan partially extends from the air inlet.

[0008] The centrifugal fan inlet is circular. When the motor drives the impeller to rotate, the arc-shaped thin plastic blades on the impeller are acted upon by centrifugal force, so that air is quickly sucked into the centrifugal fan and accelerates along the curved path of the arc-shaped thin plastic blades. Subsequently, the accelerated air is thrown to the periphery of the impeller, forming a strong airflow, and is discharged through the centrifugal fan outlet and introduced into the internal curved surface guide system. Subsequently, a low-pressure area is formed in the center of the impeller, thereby continuously sucking in new air, and the air is sucked in and discharged over and over again.

[0009] The internal curved surface guide system guides the airflow through a 3D printed curved wall surface made of resin.

[0010] When the airflow moves along the curved wall, the airflow energy loss can be reduced, the outlet jet speed can be increased as much as possible, and the thrust can be maximized. At the same time, the outlet jet system equipment can be placed in the interlayer between the curved wall and the outer shell to avoid damaging the aerodynamic shape and improve space utilization. The curved wall is embedded in the interior of the overall outer shell, and the two walls are distributed symmetrically with the center. One end of the curved wall is tangent to the circular centrifugal fan, and the other end is connected to the adjustable aperture nozzle.

[0011] The adjustable aperture nozzle is made of plastic. The adjustable aperture nozzle consists of multiple overlapping arc-shaped thin plastic blades. By rotating the knob on the back of the aperture, the separation and combination of the arc-shaped thin plastic blades can be changed, thereby changing the size of the central circular aperture and ultimately changing the gas jet volume. It has high adjustment accuracy and a large adjustment range.

[0012] The adjustable aperture nozzles are installed at two corners outside the arc-shaped wall surface. A circular opening is made on each of the three surfaces at the corner, and an adjustable aperture nozzle is respectively inlaid. A total of 6 adjustable aperture nozzles are inlaid in each housing, and a total of 12 adjustable aperture nozzles are inlaid in the left and right housings, enabling 6-degree-of-freedom movement.

[0013] Both types of gears are circular metal gears. The type-I gear is concentric with the adjustable aperture nozzle and is closely attached to the adjustable aperture nozzle. It is fixed by hot melt adhesive to rotate together with the knob on the back of the adjustable aperture. The type-II gear is vertically meshed with the type-I gear. At the same time, the center of the type-II gear is inserted into the transmission shaft and fixed with screws, and the transmission shaft is inserted into the servo motor and fixed with screws.

[0014] The servo motors are fixed to the outer shell by two groups of small screws and nuts. Two servo motors are respectively arranged at the two corners blocked by the arc-shaped wall surface. Their transmission shafts are parallel to the plane where the air inlet of the centrifugal fan air intake and pressurization system is located and pass through the small holes on the arc-shaped wall surface. One servo motor is respectively arranged at the two corners not blocked by the arc-shaped wall surface, and its transmission shaft is perpendicular to the plane where the air inlet of the centrifugal fan air intake and pressurization system is located. A total of 6 servo motors are arranged in each housing, and a total of 12 servo motors are arranged in the left and right housings. When the servo motor receives a signal and rotates a certain angle, along the transmission chain of the transmission shaft, type-II gear, and type-I gear, the opening and closing size of the adjustable aperture nozzle is controlled, thereby precisely adjusting the thrust size.

[0015] The present invention has the following beneficial effects:

[0016] 1. Using a centrifugal fan to provide power, it has sufficient thrust, low noise, and high safety factor, and is suitable for use inside the space station cabin.

[0017] 2. Using an adjustable aperture nozzle can accurately adjust the thrust size to meet the requirements of precise motion and attitude control.

[0018] 3. The transmission mechanism of the adjustable aperture nozzle has a simple structure and high reliability, and is suitable for use in the complex environment of the space station. Description of the Drawings

[0019] Figure 1 It is an integrated diagram of the main components of the space station robot propulsion system.

[0020] Figure 2 It is an isometric view of the outlet jet system of the space station robot.

[0021] Figure 3a They are respectively the front views of the adjustable aperture nozzle.

[0022] Figure 3b They are respectively the rear views of the adjustable aperture nozzle.

[0023] The descriptions of the reference numerals in the figures are as follows:

[0024] 1. Centrifugal fan, 2. Internal curved surface flow guiding system, 3. Servo steering gear, 4. Transmission shaft, 5. Type I gear, 6. Type II gear, 7. Adjustable aperture nozzle, 8. Arc-shaped thin plastic blade, 9. Outer frame, 10. Knob. Specific implementation manners

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] As Figure 1 is the main component integration diagram of the space station robot propulsion system, including a centrifugal fan 1, which can inhale and accelerate air and serve as the source of jet power. The arc-shaped wall surface of the internal curved surface flow guiding system 2 is embedded inside the overall housing, and the two wall surfaces are centrosymmetrically distributed. One end of the arc-shaped wall surface is tangent to the circular centrifugal fan, and the other end is exactly connected to the adjustable aperture nozzle. It can guide the air flow, reduce the energy loss of the air flow, and at the same time, the outlet jet system equipment can be placed in the interlayer between the arc-shaped wall surface and the housing to avoid damaging the aerodynamic shape and improve the space utilization rate.

[0027] As Figure 2 is the space station robot outlet jet system, including a servo steering gear 3, a transmission shaft 4, a Type I gear 5, a Type II gear 6, and an adjustable aperture nozzle 7. The selected servo steering gear model is SG90. The Type I gear and the adjustable aperture nozzle are concentric and closely attached to the adjustable aperture nozzle, and are fixed using hot melt adhesive. The Type II gear is vertically meshed with the Type I gear, and at the same time, the center of the Type II gear is inserted into the transmission shaft and fixed using screws. The transmission shaft is inserted into the servo steering gear 3 and fixed using screws. Circular openings are respectively opened on three surfaces at each of the two corners outside the arc-shaped wall surface, and an adjustable aperture nozzle is respectively embedded. A total of 6 adjustable aperture nozzles are embedded in each housing. Two servo steering gears are respectively arranged at the two corners blocked by the arc-shaped wall surface, and their transmission shafts are parallel to the plane where the air inlet of the centrifugal fan air intake pressurization system is located and pass through the small holes on the arc-shaped wall surface; one servo steering gear is respectively arranged at each of the two corners not blocked by the arc-shaped wall surface, and its transmission shaft is perpendicular to the plane where the air inlet of the centrifugal fan air intake pressurization system is located. 6 servo steering gears are arranged in each housing. When the servo steering gear receives a signal and rotates a certain angle (0 - 360 degrees), along the transmission chain of the transmission shaft, the Type II gear, and the Type I gear, the opening and closing size of the adjustable aperture nozzle is controlled, thereby precisely adjusting the thrust size.

[0028] As Figure 3a and Figure 3bFront and rear views of the adjustable aperture nozzle, including the arc-shaped thin plastic blade 8, the outer frame 9, and the knob 10. The adjustable aperture nozzle is composed of multiple overlapping arc-shaped thin plastic blades. By rotating the knob on the back of the aperture, the separation and combination of the arc-shaped thin plastic blades can be changed, thereby changing the size of the central circular aperture and ultimately the gas flow rate, with high adjustment accuracy and a large adjustment range.

[0029] The rotational speed of the centrifugal fan is set to 2900 rpm (±10%), and the voltage is 10 - 15V.

[0030] The following gives an example of the specific implementation with the specific movement example of the robot inside the space station cabin. When the robot is in the working state, the 12V power supply is turned on, and the centrifugal fan starts to rotate. The gas near the inlet is sucked into the housing and can reach a speed of 37.53 m / s at the outlet after acceleration. At this time, when the forward command is given, the servo motor MCU of the two adjustable aperture nozzles on the same side generates a pulse signal with a period of 20 ms, which contains a high level of 2.5 ms to make the servo motor rotate 360 degrees. The servo motor drives the type-I gear fixedly connected to it to rotate 360 degrees, and the type-II gear meshes with it and rotates 90 degrees, thereby driving the knob at the rear side of the adjustable aperture nozzle to rotate 90 degrees, making the diameter of the adjustable aperture nozzle become 50 mm, and the air flow can be ejected smoothly to provide thrust. The adjustable range of the diameter of the adjustable aperture nozzle is from 2 mm to 50 mm. After actual measurement, the adjustable range of the unilateral thrust of the robot is from 0.01 N to 0.65 N, which is sufficient to meet the thrust requirements of the space station robot.

Claims

1. A space station robot propulsion system based on an adjustable aperture nozzle, characterized in that: It includes a centrifugal fan air intake and pressure system, an internal curved surface guide system and an outlet jet control system; wherein, the air intake of the centrifugal fan air intake and pressure system is completed by the centrifugal fan; the internal curved surface guide system includes an arc-shaped wall connected to the outer shell, which is installed on the opposite side of the centrifugal fan; the outlet jet system is installed at two corners on the same diagonal line, located at the outlet of the arc-shaped wall.

2. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1, characterized in that: The overall shell of the centrifugal fan air intake and boost system is composed of two left and right rectangular shells and the middle main frame, which are fixed with bolts and nuts; the rectangular shell and the main frame are made of 3D printing, and the overall material is resin; a storage platform is installed on the upper, middle and lower sides of the main frame for placing instruments; two centrifugal fans are installed on the opposite sides of the cube, facing the center, and a circular air inlet is opened on the side of the cube, and the fan partially extends from the air inlet.

3. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1 or 2, characterized in that: The inlet of a centrifugal fan is circular. When the motor drives the impeller to rotate, the blades on the impeller are acted upon by centrifugal force, causing the air to be quickly sucked into the fan and accelerated along the curved path of the blades. The accelerated air is then thrown to the surrounding of the impeller, forming a strong airflow, which is discharged through the fan outlet and introduced into the curved guide system. A low-pressure area is then formed in the center of the impeller, thereby continuously sucking in new air, achieving a cycle of air intake and discharge.

4. The space station robot propulsion system based on an adjustable aperture nozzle according to claim 1, characterized in that: The internal curved surface guide system guides the airflow through the 3D printed curved wall, which is made of resin.

5. The space station robot propulsion system based on an adjustable aperture nozzle according to claim 4, characterized in that: When the airflow moves along the curved wall, it can reduce the energy loss of the airflow, increase the outlet jet speed, and maximize the thrust; at the same time, the outlet jet control system equipment is placed in the interlayer between the curved wall and the outer shell; the curved wall is embedded in the interior of the overall outer shell, and the two walls are distributed symmetrically with the center, one end of the curved wall is tangent to the circular centrifugal fan, and the other end is connected to the nozzle.

6. The space station robot propulsion system based on an adjustable aperture nozzle according to claim 1, characterized in that: The outlet jet control system includes a servo actuator, a transmission shaft, a type I gear, a type II gear, an adjustable aperture nozzle, screws and nuts.

7. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1 or 6, characterized in that: The adjustable aperture nozzle of the outlet jet control system is made of plastic and is composed of multiple overlapping arc-shaped thin plastic blades. By turning the knob on the back of the aperture, the clutch of the blades can be changed, thereby changing the size of the central circular aperture and ultimately changing the jet volume.

8. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1 or 6, characterized in that: The adjustable aperture nozzle of the outlet jet control system is installed at the two corners outside the curved wall. A circular opening is opened on each of the three surfaces at the corner, and an adjustable aperture nozzle is inlaid in each of them. A total of 6 adjustable aperture nozzles are inlaid in each shell, and a total of 12 adjustable aperture nozzles are inlaid in the left and right shells, realizing 6-degree-of-freedom movement.

9. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1 or 6, characterized in that: Both types of gears of the outlet jet control system are circular metal gears. Type I gear is concentric with the adjustable aperture nozzle, close to the adjustable aperture nozzle, and fixed with hot melt adhesive so that it rotates together with the knob on the back of the adjustable aperture; Type II gear is vertically meshed with Type I gear, and at the same time, the center of Type II gear is inserted into the transmission shaft and fixed with screws, and the transmission shaft is inserted into the servo steering gear and fixed with screws.

10. A space station robot propulsion system based on an adjustable aperture nozzle according to claim 1 or 6, characterized in that: The servo servo of the outlet jet control system is fixed to the outer shell by two sets of small screws and nuts; two servos are respectively arranged at the two corners where there is a curved wall blocking the view, and the transmission shaft is parallel to the plane where the air inlet of the intake and boost pressure system is located, and passes through the small holes on the curved wall; one servo is respectively arranged at the two corners where there is no curved wall blocking the view, and the transmission shaft is perpendicular to the plane where the air inlet of the intake and boost pressure system is located; six servos are arranged in each shell, and a total of 12 servos are arranged in the left and right shells.

Images