Water rescue unmanned aerial vehicle

Abstract

The water rescue unmanned aerial vehicle comprises a vehicle body provided with a wireless remote controller, a rotating telescopic mechanism arranged on the vehicle body and a rotor wing mechanism adjustably arranged on the rotating telescopic mechanism, and the rotating telescopic mechanism comprises a rotating assembly arranged on the vehicle body and an air cushion groove assembly connected with the rotating assembly; a telescopic net is arranged on the outer side of the air cushion groove assembly, an inflatable air cushion is arranged on the inner side of the air cushion groove assembly, and the rotating assembly, the rotor wing mechanisms and the inflatable air cushion are all connected with a wireless remote controller. The high maneuverability and flexibility of the unmanned aerial vehicle are utilized, the rotary stretching mechanism is arranged to stretch and extend the telescopic net, and a rescued person can be rapidly and safely transferred on the water surface through mutual combined use of the air cushion capable of being rapidly inflated and the rotor wing mechanism, so that the purpose of efficient rescue operation is achieved.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a water rescue UAV. Background Technology

[0002] Currently, the widely used drowning rescue drones mainly operate from the air, primarily locating drowning victims and airdropping equipment such as lifebuoys and buoyancy ropes. However, they are ineffective in situations where drowning victims are struggling violently and unable to grasp the airdropped equipment (e.g., due to exhaustion or loss of consciousness). Furthermore, the accuracy of airdrops is greatly affected by wind and water currents, often resulting in equipment drifting to areas out of reach of the drowning victim.

[0003] While existing water rescue robots (such as surface-propelled rescue boats) can move on the water and approach drowning victims, they need to be deployed from the shore or boats, resulting in slow response times (especially in remote waters). Underwater robots (such as ROVs) can operate underwater, but they rely on cable connections or pre-deployment, making it difficult to quickly reach the rescue point from land or air. Furthermore, their operation is complex and unsuitable for emergency rescue scenarios. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a water rescue drone that can quickly reach the rescue site and quickly carry out rescue transfer.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: providing a water rescue drone, including a body equipped with a wireless remote controller, a rotating telescopic mechanism disposed on the body, and an adjustable rotor mechanism disposed on the rotating telescopic mechanism. The rotating telescopic mechanism includes a rotating component disposed on the body and an air cushion groove component connected to the rotating component. A telescopic net is disposed on the outside of the air cushion groove component, and an inflatable air cushion is disposed on the inside of the air cushion groove component. The rotating component, the rotor mechanism, and the inflatable air cushion are all connected to the wireless remote controller.

[0006] The above structure incorporates a wireless remote controller on the fuselage, which can receive remote control signals and promptly send corresponding instructions to the rotating components, rotor mechanism, and inflatable air cushion to enable appropriate rescue operations. The rotating telescopic mechanism facilitates the deployment of the rotor mechanism while simultaneously extending the telescopic net, effectively preventing accidental injury to the rescued person by the rotor. The inflatable air cushion facilitates lifting the rescued person from underwater and, in conjunction with the rotor mechanism, achieves the goal of quickly transferring the rescued person. The structure is simple, compact, and easy to operate.

[0007] To simplify the structure and facilitate installation, preferably, the rotating assembly includes a power motor fixed to the body, a connecting plate connected to the output end of the power motor, and a first connecting rod, a second connecting rod, a third connecting rod, and a fourth connecting rod rotatably connected to the connecting plate. The power motor is connected to a wireless remote control controller.

[0008] To facilitate installation and avoid interference from movement, preferably, two first pins are symmetrically provided on the upper end face of the connecting plate, and two second pins are symmetrically provided on the lower end face of the connecting plate. The two first pins and the two second pins are staggered. One side of the first link and the third link are respectively sleeved with the two first pins, and one side of the second link and the fourth link are respectively sleeved with the two second pins.

[0009] To simplify the installation structure and ensure consistent performance in overall use, the air cushion groove assembly preferably includes a first air cushion groove, a second air cushion groove, a third air cushion groove, and a fourth air cushion groove that enclose a frame-like structure. The outer walls of all four air cushion grooves are connected to a telescopic net. A first support rod is provided at the lower end of the outer wall of the first and third air cushion grooves, and a second support rod is provided at the lower end of the outer wall of the second and fourth air cushion grooves. Guide components are provided on both the first and second support rods.

[0010] To ensure smooth operation and ease of installation, preferably, the guide assembly includes a first collar on the other side of both the first and third connecting rods, and a second collar on the other side of both the second and fourth connecting rods. The first support rod passes through the first collar at a corresponding position, and a first guide rod is connected to the protruding end of the first support rod. A first guide sleeve is provided on the machine body at a position corresponding to the first guide rod, and the first guide rod is placed inside the first guide sleeve. Similarly, a second collar is provided on the other side of both the second and fourth connecting rods, and a second support rod passes through the second collar at a corresponding position. A second guide rod is connected to the protruding end of the second support rod. A second guide sleeve is provided on the machine body at a position corresponding to the second guide rod, and the second guide rod is placed inside the second guide sleeve.

[0011] For ease of installation and organization, preferably, each of the air cushion slots is equipped with a miniature air pump connected to a wireless remote controller, and each miniature air pump is connected to the inflatable air cushion in the corresponding air cushion slot.

[0012] To facilitate the concealment of air cushion leakage and to allow the air cushion to extend and expose the air cushion grooves during inflation, preferably, a cover plate is hinged at the opening of each of the four air cushion grooves. A bent section is provided at the non-hinged end of the cover plate, and a boss is provided on the inner side wall of the bent section. The protruding end of the boss abuts against and limits the outer side wall of the air cushion groove.

[0013] To facilitate adjustment of the drone's direction of movement, preferably, the rotor mechanism includes a support rod extending horizontally from each of the air cushion grooves and a servo motor fixed on the support rod. The servo motor is connected to a wireless remote controller. A connecting shaft is provided at the output end of the servo motor. The connecting shaft is fixedly connected to one side of the engine. The output end of the engine is connected to the rotating blades.

[0014] To better avoid injury to those being rescued, it is preferable to attach a protective ring to the outer wall of the engine, which is wrapped around the outside of the rotating blades.

[0015] To better observe and locate the position of the person being rescued, it is preferable to have a camera installed on one side of the machine body.

[0016] Beneficial effects: This invention utilizes the high mobility and flexibility of drones, and sets up a rotating and stretching mechanism to stretch and extend the telescopic net. Combined with a rapidly inflatable air cushion and a rotor mechanism, it can quickly and safely transfer rescued persons on the water surface, thereby achieving the goal of efficient rescue operations. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 for Figure 1 View A in the diagram.

[0019] Figure 3 This is a schematic diagram of the installation structure of the first air cushion groove.

[0020] Figure 4 This is a schematic diagram of the cover plate's installation structure.

[0021] Figure 5 This is a schematic diagram of the rotor mechanism.

[0022] Figure 6 This is a schematic diagram of the structure of the present invention when unfolded.

[0023] Figure 7 for Figure 6 View B in the diagram.

[0024] Figure 8 This is a diagram showing the usage state of the present invention during translation.

[0025] The meanings of the labels in the attached diagram are as follows: Body-1; Wireless remote controller-10; First guide sleeve-11; Second guide sleeve-12; Power motor-2; connecting plate-20; first link-21; second link-22; third link-23; fourth link-24; first pin-201; second pin-202; first collar-203; second collar-204; Telescopic net - 3; Inflatable air cushion - 30; Cover plate - 31; Bending section - 310; Boss - 32; Miniature air pump - 33; First air cushion groove - 41; Second air cushion groove - 42; Third air cushion groove - 43; Fourth air cushion groove - 44; First support rod - 45; Second support rod - 46; First guide rod - 47; Second guide rod - 48; Support rod-5; Servo motor-50; Engine-51; Rotary blade-52; Protective ring-53; Camera-6. Detailed Implementation

[0026] Depend on Figures 1 to 8 As shown, the present invention includes a body 1 equipped with a wireless remote controller 10, a rotating telescopic mechanism disposed on the body 1, and an adjustable rotor mechanism disposed on the rotating telescopic mechanism. The rotating telescopic mechanism includes a rotating component disposed on the body 1 and an air cushion groove component connected to the rotating component. A telescopic net 3 is disposed on the outer side of the air cushion groove component, and an inflatable air cushion 30 is disposed on the inner side of the air cushion groove component. The rotating component, the rotor mechanism, and the inflatable air cushion 30 are all connected to the wireless remote controller 10.

[0027] Specifically, the rotating assembly includes a power motor 2 fixed on the body 1, a connecting plate 20 connected to the output end of the power motor 2, and a first connecting rod 21, a second connecting rod 22, a third connecting rod 23, and a fourth connecting rod 24 rotatably connected to the connecting plate 20. The power motor 2 is connected to the wireless remote controller 10. Two first pins 201 are symmetrically provided on the upper end face of the connecting plate 20, and two second pins 202 are symmetrically provided on the lower end face of the connecting plate 20. The two first pins 201 and the two second pins 202 are staggered. One side of the first connecting rod 21 and the third connecting rod 23 is respectively sleeved with the two first pins 201, and one side of the second connecting rod 22 and the fourth connecting rod 24 is respectively sleeved with the two second pins 202.

[0028] The air cushion groove assembly includes a first air cushion groove 41, a second air cushion groove 42, a third air cushion groove 43, and a fourth air cushion groove 44 that are arranged in a frame-like structure. The outer walls of the four air cushion grooves are all connected to the telescopic net 3. A first support rod 45 is provided at the lower end of the outer wall of the first air cushion groove 41 and the third air cushion groove 43, and a second support rod 46 is provided at the lower end of the outer wall of the second air cushion groove 42 and the fourth air cushion groove 44. Guide components are provided on the first support rod 45 and the second support rod 46.

[0029] The guiding assembly includes a first collar 203 provided on the other side of the first connecting rod 21 and the third connecting rod 23, and a second collar 204 provided on the other side of the second connecting rod 22 and the fourth connecting rod 24. The first support rod 45 at the corresponding position passes through the first collar 203, and the protruding end of the first support rod 45 is connected to a first guide rod 47. A first guide sleeve 11 is provided on the body 1 at the position corresponding to the first guide rod 47, and the first guide rod 47 is placed inside the first guide sleeve 11. A second collar 204 is provided on the other side of the second connecting rod 22 and the fourth connecting rod 24, and a second support rod 46 at the corresponding position passes through the second collar 204. The protruding end of the second support rod 46 is connected to a second guide rod 48. A second guide sleeve 12 is provided on the body 1 at the position corresponding to the second guide rod 48, and the second guide rod 48 is placed inside the second guide sleeve 12.

[0030] Each of the air cushion slots is equipped with a miniature air pump 33 connected to the wireless remote controller 10, and each miniature air pump 33 is connected to the inflatable air cushion 30 in the corresponding air cushion slot. A cover plate 31 is hinged at the opening of each of the four air cushion slots. A bent section 310 is provided at the non-hinged end of the cover plate 31. A boss 32 is provided on the inner side wall of the bent section 310. The protruding end of the boss 32 abuts against and limits the outer side wall of the air cushion slot.

[0031] The rotor mechanism includes a support rod 5 extending horizontally from each of the air cushion grooves and a servo motor 50 fixed on the support rod 5. The servo motor 50 is connected to the wireless remote controller 10. A connecting shaft is provided at the output end of the servo motor 50. The connecting shaft is connected and fixed to one side of the engine 51. The output end of the engine 51 is connected to the rotating blade 52. A protective ring 53 is connected to the outer wall of the engine 51 and is wrapped around the outside of the rotating blade 52.

[0032] A camera 6 connected to a wireless remote controller (not shown) is also provided on one side of the body 1.

[0033] The working principle of this invention is as follows: like Figure 1 and Figure 2As shown, before the drone takes off from the land, the four air cushion slots retract and fit against the body 1 to ensure minimal flight resistance. When someone is found in distress on the water, the operator sends a command to the wireless remote controller 10 through a wireless remote controller with a screen (including joystick, number keys, and function keys). This commands the engine 51 to start, causing the rotor blades 52 to rotate. This allows the drone body 1 to take off from the land and ascend vertically to a height of 10 meters using the remote controller's lifting joystick. The cameras 6 on both sides of the body 1 then perform a large-scale water search.

[0034] After the camera captures the distressed person, it uses image transmission navigation to reach the airspace above the distressed person's waters, and then descends to a height of 5-8m above the distressed person to hover and wait: combining GPS and image transmission from the camera, the drone maintains a horizontal distance from the distressed person to ensure stable hovering.

[0035] Next, the operator uses the wireless remote control to reduce the speed of engine 51, that is, to reduce the speed of the rotating blades 52, so that the drone begins to descend. When it reaches the water surface, since the overall weight of the drone is greater than the buoyancy of the water of the same area, the drone itself does not have positive buoyancy and will sink naturally on the water surface. At this time, the rotor mechanism mainly controls the attitude and speed of the drone to make it descend stably. The thrust generated by the rotating blades 52 is equivalent to providing "air damping" for the drone, so that it can descend smoothly at a controllable speed to keep the openings of the four air cushion slots facing upwards.

[0036] After the drone was completely submerged in the water, the operator immediately pressed the "Frequency Switch" button on the wireless remote controller to switch the remote control signal from 2.4GHz to 433MHz, and toggled the "Camera Control" button to switch the camera's 6-angle view from overhead to upward, so as to observe the spatial position between the drone and the person in distress on the screen of the wireless remote controller, which helps to quickly adjust the drone's position underwater.

[0037] Specifically, the operator reduces the rotational speed of the rotor blades 52 by continuously reducing the rotational speed of the engine 51, thereby reducing the upward lift and allowing the drone to continue sinking after reaching the water surface. During the sinking process, the operator fine-tunes the rotational speed of the rotor blades 52 to control the sinking speed and position; that is, if a faster sinking is needed, the rotational speed is reduced further. When the drone descends to a depth of 0.5-1.0 meters below the body of the person in distress, the operator observes the upward-looking image transmitted by the camera 6 and increases the rotational speed of the rotor blades 52 to generate greater lift to balance the drone's gravity, thus achieving a hovering state of the drone underwater.

[0038] Next, while hovering, the operator observes the real-time feed from camera 6 to determine the relative position of the center of the distressed person's body to the center of the drone. Then, using the roll and pitch joysticks on the remote controller, the operator inputs a horizontal movement command to increase the rotational speed of the two adjacent rotors in the same direction. As a result, under the influence of the speed difference, the entire drone body 1 is positioned at an angle underwater (the one with the higher rotational speed is at the higher end). The two high-speed rotor blades 52 are then adjusted to return to the same rotational speed as the other two rotor blades 52. Combined with the horizontal component of the rotation of the rotor blades 52, the drone maintains horizontal movement underwater.

[0039] like Figures 1 to 7 As shown, after the drone moves into position, the rotation speed of the two corresponding rotating blades 52 is reduced to bring the body 1 back to a horizontal position. After adjusting the rotation speed of the four rotating blades 52 to be consistent, the drone returns to a horizontal hovering state underwater. The operator presses the "arm deployment" button on the remote control, and the wireless remote controller 10 sends a start command to the power motor 2, which drives the connecting plate 20 to rotate. This causes the first connecting rod 21, the second connecting rod 22, the third connecting rod 23, and the fourth connecting rod 24, which are connected to the first pin 201 and the second pin 202, to move synchronously. At the same time, the first collar 203 and the second collar 204, which are fixed on the four connecting rods, respectively, drive the first support rod 45 and the second support rod 46, which are connected to it, to move synchronously. This allows the first guide rod 47 and the second guide rod 48, which are connected to the first support rod 45 and the second support rod 46, to move synchronously within the first guide sleeve 11 and the second guide sleeve 12, thereby forming a state in which the four air cushion grooves move outward and expand. At this time, the telescopic net 3 is stretched and deployed synchronously and is located directly below the body of the person in distress.

[0040] Then, the operator presses the "buoyancy release" button on the wireless remote controller, which sends a start command to the miniature air pump 33. The miniature air pump 33 inflates the air cushion 30, achieving 100% inflation in a short time, and the cushions pop out of the air cushion slots. The four inflatable air cushions 30 generate a total buoyancy of ≥1500N. During this process, to prevent the air cushions 30 from falling out of the air cushion slots due to airflow during drone flight, a cover plate 31 is hinged at the opening of each air cushion slot. A bent section 310 is provided at the non-hinged end of the cover plate 31. A boss 32 is provided on the inner side wall of the bent section 310. The protruding end of the boss 32 abuts against the outer side wall of the air cushion groove to limit the movement, thereby preventing the inflatable air cushion 30 from falling out. When the inflatable air cushion 30 is fully inflated, the expansion force of the inflatable air cushion 30 will overcome the abutment resistance of the boss 32 and drive the non-hinged end of the cover plate 31 to move, so that the non-hinged end of the cover plate 31 is opened from the groove, thereby satisfying the use state of the inflatable air cushion 30 being fully inflated out of the air cushion groove.

[0041] Due to the drone's hovering state, the inflatable air cushion 30, buoyant in the water, allows the drone to slowly rise, bringing the air cushion 30 into contact with the lower surface of the victim's body, thus supporting the victim. At this point, the rotation speed of the propellers 52 is accelerated to quickly lift the victim's body out of the water. It should be noted that, as the propellers 52 extend horizontally outward with the deployment of the air cushion, the four propellers 52 should be positioned on the outer sides of the victim's shoulders and feet. This ensures that even if the victim is unconscious, the rotation of the propellers 52 will not cause limb injury. Additionally, a protective ring 53 is provided in the horizontal direction of the propellers 52, further protecting against injury.

[0042] The person in distress, lifted out of the water, continues to descend under the influence of gravity (mainly the waist and abdomen) and lands on the extended telescopic net 3. Consequently, the person's limbs also move slightly towards the center of the drone. At this point, the operator presses the corresponding "vector adjustment" button on the wireless remote controller 10, which activates the two corresponding servo motors 50 on the same side, simultaneously driving the two corresponding engines 51 to rotate the drone body. This, in turn, rotates the two corresponding rotating propellers 52 to a vertical position (e.g., ...). Figure 8 As shown), the rotational speed of the two vertically positioned rotating blades 52 is then increased, thereby generating forward thrust and propelling the machine towards the shore at a speed of 1-2 m / s; while the two rotating blades 52 that have not been adjusted remain in a horizontal position and their rotational speed is appropriately increased but less than that of the vertically positioned rotating blades 52, in order to adapt to the water flow interference on the water surface and ensure the horizontal stability of the machine body 1 as it moves on the water surface.

[0043] Among these, such as Figure 1 , Figure 3 as well as Figure 4 As shown, the miniature air pump 33 is located at the bottom of each air cushion groove. When not in use, the connected inflatable air cushion 30 covers the outside of the miniature air pump 33, and then the cover plate 31 covers the outside of the inflatable air cushion 30, which facilitates folding and also prevents the inflatable air cushion 30 from escaping. Since the installation structure of the first air cushion groove 41, the second air cushion groove 42, the third air cushion groove 43, and the fourth air cushion groove 44 is the same, to avoid repetition of the illustrations, only the installation structure of the first air cushion groove 41 is described. Figure 3 and Figure 4 The diagram is shown in the image.

[0044] Meanwhile, to facilitate timely adjustment of the movement direction, each servo motor 50 should be equipped with a corresponding "vector adjustment" button on the wireless remote control. In this way, if the direction changes during the transfer to shore, the corresponding servo motor 50 can be activated in time to drive the rotating blade 52 to rotate to the vertical position, and at the same time, the corresponding rotating blade 52 can be controlled to move back to the horizontal position to improve rescue efficiency.

[0045] It should be noted that the drone body 1 is also equipped with a water depth sensor, an angle sensor, and a GPS module (none of which are labeled), and all of them should be connected to the wireless remote controller 10. The sensor data is transmitted back to the remote controller screen in real time, so as to effectively determine the drone's diving depth, usage attitude, and spatial location during the rescue process, which helps the operator to judge the timing of the operation and adjust the usage status in a timely manner.

[0046] All electronic components installed on the body 1 should be waterproofed. The rescue setup to be protected in this application, given the existing technology of underwater drones, and the structure corresponding to the body 1 in this application, will not be described in detail here without hindering wireless data transmission.

Claims

1. A water rescue drone, characterized in that: The device includes a body (1) equipped with a wireless remote controller (10), a rotating telescopic mechanism mounted on the body (1), and an adjustable rotor mechanism mounted on the rotating telescopic mechanism. The rotating telescopic mechanism includes a rotating component mounted on the body (1) and an air cushion groove component connected to the rotating component. A telescopic net (3) is provided on the outside of the air cushion groove component, and an inflatable air cushion (30) is provided on the inside of the air cushion groove component. The rotating component, the rotor mechanism, and the inflatable air cushion (30) are all connected to the wireless remote controller (10).

2. The water rescue drone as described in claim 1, characterized in that: The rotating assembly includes a power motor (2) fixed on the body (1), a connecting plate (20) connected to the output end of the power motor (2), and a first connecting rod (21), a second connecting rod (22), a third connecting rod (23) and a fourth connecting rod (24) rotatably connected to the connecting plate (20). The power motor (2) is connected to the wireless remote controller (10).

3. A water rescue drone as described in claim 2, characterized in that: Two first pins (201) are symmetrically provided on the upper end face of the connecting plate (20), and two second pins (202) are symmetrically provided on the lower end face of the connecting plate (20). The two first pins (201) and the second pins (202) are staggered with each other. One side of the first link (21) and the third link (23) are respectively sleeved with the two first pins (201), and one side of the second link (22) and the fourth link (24) are respectively sleeved with the two second pins (202).

4. The water rescue drone as described in claim 3, characterized in that: The air cushion groove assembly includes a first air cushion groove (41), a second air cushion groove (42), a third air cushion groove (43), and a fourth air cushion groove (44) that are enclosed to form a frame structure. The outer walls of the four air cushion grooves are all connected to the telescopic net (3). A first support rod (45) is provided at the lower end of the outer wall of the first air cushion groove (41) and the third air cushion groove (43), and a second support rod (46) is provided at the lower end of the outer wall of the second air cushion groove (42) and the fourth air cushion groove (44). Guide components are provided on the first support rod (45) and the second support rod (46).

5. A water rescue drone as described in claim 4, characterized in that: The guide assembly includes a first collar (203) provided on the other side of the first connecting rod (21) and the third connecting rod (23), and a second collar (204) provided on the other side of the second connecting rod (22) and the fourth connecting rod (24). The first support rod (45) at the corresponding position passes through the first collar (203), and the protruding end of the first support rod (45) is connected to a first guide rod (47). A first guide sleeve (11) is provided on the body (1) at the position corresponding to the first guide rod (47). The first guide rod (47) is placed inside the first guide sleeve (11); a second collar (204) is provided on the other side of the second connecting rod (22) and the fourth connecting rod (24), and the second support rod (46) at the corresponding position passes through the second collar (204). The protruding end of the second support rod (46) is connected to the second guide rod (48), and a second guide sleeve (12) is provided on the body (1) at the position corresponding to the second guide rod (48). The second guide rod (48) is placed inside the second guide sleeve (12).

6. A water rescue drone as described in claim 4, characterized in that: Each of the air cushion slots is equipped with a miniature air pump (33) connected to a wireless remote controller (10), and each miniature air pump (33) is connected to the inflatable air cushion (30) in the corresponding air cushion slot.

7. A water rescue drone as described in claim 4, characterized in that: A cover plate (31) is hinged to the opening of each of the four air cushion grooves. A bent section (310) is provided at the non-hinged end of the cover plate (31). A boss (32) is provided on the inner side wall of the bent section (310). The protruding end of the boss (32) abuts against and limits the outer side wall of the air cushion groove.

8. A water rescue drone as described in claim 4, characterized in that: The rotor mechanism includes a support rod (5) extending horizontally on each of the air cushion grooves and a servo motor (50) fixed on the support rod (5). The servo motor (50) is connected to a wireless remote controller (10). A connecting shaft is provided at the output end of the servo motor (50). The connecting shaft is connected and fixed to one side of an engine (51). The output end of the engine (51) is connected to a rotating blade (52).

9. A water rescue drone as described in claim 8, characterized in that: A protective ring (53) is connected to the outer wall of the engine (51) and is wrapped around the outside of the rotating blade (52).

10. A water rescue drone as described in claim 1, characterized in that: A camera (6) is provided on one side of the body (1).

Images