Double-wheel leg tip end logistics distribution robot

Abstract

This invention discloses a dual-wheeled legged end-of-life delivery robot, comprising a leg linkage system and a vehicle body. The leg linkage system is a parallel mechanism, forming a seven-bar linkage with the vehicle body. The vehicle body is equipped with a front-facing camera, below which is an ultrasonic sensor. A robotic arm is housed within the vehicle body, and a lidar transmitter is located on the upper rear of the vehicle body. A storage box is located below the robotic arm's base, and an ESC board, a development board, and a Raspberry Pi development board are located above the storage box. This invention employs a combination of lidar and vision to detect changes in the external environment in real time, enabling the robot to avoid obstacles and perform reasonable path planning during delivery. The robotic arm, in conjunction with the camera, autonomously presses elevator buttons, achieving precise button presses by calculating the distance from the control lever to the button. The height-adjustable dual-wheeled legs maintain the robot's balance and stability at all times through gyroscope detection, meeting the end-of-life delivery needs of delivery service robots for food delivery, express delivery, and other similar services.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology and relates to a two-wheeled legged end-effector delivery robot, specifically a two-wheeled legged autonomous navigation mobile robot based on ROS, which can deliver takeout, express delivery and other items to customers. Specifically, it is characterized by agile movement, accurate positioning, adaptability to uneven terrain, and efficient completion of delivery tasks. Background Technology

[0002] As the food delivery, express delivery, and hotel service industries move towards intelligent and unmanned operations, the demand for delivery service robots is becoming increasingly prominent. Currently, most food delivery and express delivery services store items at service stations near customers, leaving the distance between the customer and the station as a service blind spot, thus failing to provide a sense of convenience. Therefore, there is a need to develop dedicated delivery service robots to complete the last leg of the "goods-to-people" delivery journey, indicating significant development potential for last-mile logistics equipment. At present, delivery service robots mainly use three-wheeled or four-wheeled chassis, resulting in a large size, slow operating speed, and significant limitations on uneven surfaces, making them unable to avoid dangers in complex situations. Furthermore, to address the issue of robots crossing floors, some buildings have modified the electrical equipment of elevators to allow robots to connect to the elevators via radio frequency and send and receive commands, enabling robots to acquire and control the elevator's operating status. Other robots require human assistance to control the elevators. While this solves the problem of robots using elevators, it also limits their application scope to some extent. In this context, to meet the demand for intelligent service robots that connect "things and people," it is necessary to design and develop a robot that is agile, has accurate positioning, is small in size, adaptable to different terrains, can autonomously go up and down stairs, and can efficiently complete tasks. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-wheeled, legged end-effector delivery robot to improve work safety and efficiency, and achieve more efficient delivery services.

[0004] The technical solution adopted in this invention is as follows: the robot includes a leg support system and a vehicle body;

[0005] The outrigger linkage is a parallel mechanism forming a seven-bar linkage with the vehicle body. Two sets of three-bar linkages are symmetrically distributed. In each set, the two second-order links are hinged together at their midpoints, and their upper ends are respectively hinged to the lower part of the third-order link. The upper part of each third-order link is hinged to a shoulder on the vehicle body via a servo motor and main steering disc. A limiting ring is provided on the outer side of the shoulder to restrict the rotation angle of the third-order link. The lower ends of the two second-order links are respectively hinged to the upper parts of the first and fourth-order links. The lower part of the first-order link is fixedly connected to the outer ring of a bearing, and the inner ring of the bearing is fixedly connected to the fixed bushing of a brushless DC motor. The lower part of the fourth-order link is fixed to the fixed bushing of the brushless DC motor. The output shaft of the brushless DC motor is connected to the wheel, enabling the brushless DC motor to drive the wheel to rotate. The midpoints of the first and fourth-order links are respectively hinged to one side of the support leg linkage, and the other side of the support leg linkage is respectively connected to the upper part of the support leg. A guide wheel is installed at the lower end of the support leg. The first-order link is constrained by a stop plate.

[0006] A front-facing camera is located on the outer front of the vehicle body, mounted on a camera base fixed to the vehicle body via a camera bracket. An ultrasonic sensor is fixed below the front-facing camera. Inside the vehicle body is a robotic arm. The robotic arm base is connected to the first-stage arm via a digital servo motor, the first-stage arm is connected to the second-stage arm via a digital servo motor, and the second-stage arm is connected to the output shaft via a digital servo motor. A camera used to identify the button positions and digital information of the elevator button panel is fixed to the upper and front parts of the robotic arm's control lever. A lidar transmitter is located on the upper rear of the vehicle body, driven by a DC motor via a belt and pulley. The lower part of the robotic arm base is a storage box, and the upper part of the storage box houses an ESC (Electronic Speed ​​Controller), a development board, and a Raspberry Pi development board. The ESC controls the rotation of the DC brushless motor. The development board and the Raspberry Pi development board communicate via a serial port, and the development board controls the movement of the robotic arm's control lever.

[0007] This invention primarily employs a combination of LiDAR and vision to detect changes in the external environment in real time, enabling the robot to avoid obstacles and plan reasonable paths during delivery. A retractable robotic arm, in conjunction with a camera, autonomously presses elevator buttons, calculating the distance from the control lever to the button for precise button operation. Liftable dual-wheeled legs, monitored by a gyroscope, maintain the robot's balance and stability at all times, allowing free movement on any surface. This solution meets the needs of delivery service robots for last-mile logistics such as food delivery and express delivery. The beneficial effects of this invention are: by using technologies such as ultrasonic sensors, LiDAR, gyroscopes, vision detection, and dual-wheeled leg control, this invention improves upon existing building robots' problems of inaccurate positioning, slow operating speed, untimely obstacle avoidance, and poor ground adaptability. This invention uses ultrasonic sensors and a vision detection module for close-range obstacle avoidance, while LiDAR enables overall route planning. This combination of near and far-range detection allows the robot to adapt to changes in the external environment, avoid obstacles promptly, and plan reasonable paths, thus improving the safety of building robots. Utilizing visual positioning technology, the robot can acquire real-time position and digital information of elevator buttons. By continuously calculating the distance between the buttons and the robotic arm, precise button selection for different floors is achieved, enabling intelligent elevator movement without altering the internal structure and demonstrating strong versatility. During goods transportation, the wheeled robot lowers its two legs, reducing its center of gravity and ensuring smoother operation. Simultaneously, a six-axis gyroscope monitors the robot's posture in real-time, ensuring the robot remains balanced at all times. When traversing uneven surfaces, the robot adjusts the height of its two legs to maintain stability, ensuring items remain horizontal during transport, making it suitable for the safe transport of fragile goods. This increases operating speed, improves delivery efficiency, and saves significant manpower and resources. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the stair button of the present invention;

[0009] Figure 2 This is a schematic diagram of the support leg system of the present invention; wherein (a) is a schematic diagram of the structure when it moves to the highest position; and (b) is a schematic diagram of the structure when it moves to the lowest position.

[0010] Figure 3 This is a schematic diagram of the structure of the limiting ball and the limiting ball seat of the present invention; wherein (a) is the front view; and (b) is the top view.

[0011] Figure 4 This is a schematic diagram of the development board and storage box of the present invention;

[0012] Figure 5 This is a schematic diagram of the structure of the robotic arm of the present invention;

[0013] Figure 6This is a schematic diagram of the structure of the sensor element of the present invention;

[0014] Figure 7 This is a schematic diagram of the invention operating on uneven road surfaces;

[0015] Figure 8 This is a schematic diagram of the control principle of the present invention.

[0016] In the diagram: 1-Outrigger system; 2-Vehicle body; 3-Robotic arm; 4-Elevator button panel;

[0017] 101-Guide wheel; 102-Support leg; 103-Baffle; 104-DC brushless motor; 105-Fixed bushing; 106-Screw 1; 107-Support leg connecting rod; 108-Screw 2; 109-Screw 4; 110-Limit ball; 111-Bolt; 112-Screw 3; 113-Shoulder; 114-Limit ball seat; 115-Servo; 116-Limit ring; 117-Wheel; 201-ESC center plate; 202-Development board; 203-Raspberry Pi development board; 204-Storage box cover; 205-Storage box Side panel; 206-Rear side panel of storage box; 207-Bottom panel of storage box; 241-Camera base; 242-Front-facing camera; 243-Camera bracket; 244-Ultrasonic sensor; 245-LiDAR transmitter; 246-Belt; 247-Pulley; 248-DC motor; 301-Robotic arm base; 302-First-stage arm; 303-Second-stage arm; 304-Digital servo motor three; 305-Camera; 306-Output shaft; 307-Robotic arm control lever; 308-Digital servo motor two; 309-Digital servo motor one. Detailed Implementation

[0018] like Figure 1 As shown, camera 305 acquires elevator button position information and transmits it to development board 202. After processing the signal, development board 202 controls servo motor 115 to drive lever 112, raising vehicle body 2 to the required height. Camera 305, fixed on the mobile robotic arm 3, extracts information from the digital buttons on the elevator to locate specific floor buttons. Finally, the robotic arm's control lever 307 completes the button operation. After the button operation is completed, the vehicle body descends to its lowest position, lowering the vehicle's center of gravity.

[0019] like Figure 2 , Figure 4 , Figure 5 , Figure 6 As shown, the present invention includes a support leg system 1 and a vehicle body 2;

[0020] The outrigger linkage 1 is a parallel mechanism that forms a seven-bar linkage with the vehicle body 2. Two sets of three-bar linkages are symmetrically distributed. The two second-order links 108 in each set are hinged together at their midpoints by bolts 111. The upper ends of these two second-order links 108 are respectively hinged to the lower parts of the third-order link 112 by bolts 111. The upper part of each third-order link 112 is hinged to a shoulder 113 on the vehicle body 2 via a servo motor 115 and a main steering disc. A limiting ring 116 is provided on the outer side of the shoulder 113 to restrict the rotation angle of the third-order link 112. The lower ends of the two second-order links 108 are respectively hinged to the upper parts of the first-order link 106 and the fourth-order link 109 by bolts 111. The lower part of the first-order link 106 is fixedly connected to the outer ring of a bearing, and the inner ring of the bearing is fixedly connected to the fixed bushing 105 of the DC brushless motor 104. The lower part of the fourth-order link 109 is fixed to the fixed bushing 105 of the DC brushless motor 104 by bolts. The output shaft of the brushless DC motor 104 is connected to the wheel 117, enabling the brushless DC motor 104 to drive the wheel 117 to rotate. The middle portions of rod 106 and rod 109 are hinged to one side of the support leg connecting rod 107, and the other side of the support leg connecting rod 107 is connected to the upper part of the support leg 102. A guide wheel 101 is installed at the lower end of the support leg 102. Rod 106 is constrained by a stop plate 103. The first rod 106 and the fourth rod 109 are symmetrically hinged to the support leg 102 and the support leg connecting rod 107 by bolts, respectively. During the rise and fall of the support leg system 1, the position of the support leg 102 also changes continuously with the opening angle of the first rod 106 and the fourth rod 109. When it rises to the highest point, the support leg 102 contacts the ground, ensuring that the robot of the present invention stands safely and stably. When performing delivery work, the support leg 102 is raised, and the movement of the trolley is more flexible. In case of an emergency, when the trolley body tilts to a certain angle, the support leg 102 contacts the ground, limiting the overall tilt angle of the robot of the present invention and ensuring that the trolley does not fall over.

[0021] like Figure 3 As shown, a limiting ball 110 is provided on the outer side of the hinge position of the two No. 2 rods 108 in one set. The limiting ball 110 corresponds to the limiting ball seat 114 on the lower part of the vehicle body 2. When the vehicle body 2 is lowered to the lowest position, the limiting ball 110 falls into the spherical seat of the limiting ball seat 114 to enhance the stability of the outrigger rod system 1.

[0022] A front-facing camera 242 is located on the outer front side of the vehicle body 2. This camera is mounted on a camera base 241 fixed to the vehicle body 2 via a camera bracket 243. An ultrasonic sensor 244 is fixed below the front-facing camera 242. Inside the vehicle body 2 is a robotic arm 3. The robotic arm base 301 is connected to the first-stage arm 302 via a digital servo motor 309. The first-stage arm 302 is connected to the second-stage arm 303 via a digital servo motor 308. The second-stage arm 303 is connected to the output shaft 306 via a digital servo motor 304. A camera 305, used to identify the button positions and digital information of the elevator button panel 4, and a robotic arm operating lever 307 are fixed to the upper and front parts of the output shaft 306. A laser radar emitter 245 is located on the upper rear of the vehicle body 2. This laser radar emitter 245 is driven by a DC motor 248 via a belt 246 and a pulley 247. A storage box is located below the robotic arm base 301.

[0023] like Figure 4 As shown, the storage box consists of a base plate 207, side plates 205, a cover plate 204, and a rear side plate 206, all fixedly connected by angle iron. Located at the bottom of the vehicle body 2, it ensures a low center of gravity for the wheeled robot and is primarily used to store takeout, express delivery, and other items. The robotic arm base 301 is fixed to the cover plate 204. The upper part of the cover plate 204 also houses an ESC board 201, a development board 202, and a Raspberry Pi development board 203. The ESC board 201 controls the rotation of the brushless DC motor 104, and the development board 202 communicates with the Raspberry Pi development board 203 via a serial port. The development board 202 controls the movement of the robotic arm's control lever 307.

[0024] like Figure 6 , Figure 7 , Figure 8 As shown, the Raspberry Pi development board 203 acts as the host computer, receiving data from the lidar transmitter 245. By analyzing the data, it constructs a map of the current building and plans a path. Then, it converts the required actions into electrical signals and transmits them to the slave development board 202. Information exchange is completed via serial communication. The development board 202 determines the robot's movement based on the data from the host computer Raspberry Pi development board 203. The development board 202 transmits the data to the ESC (Electronic Speed ​​Controller) board 201 via serial port. The ESC board 201 controls the brushless DC motors 104 on the sides of the wheels 117, enabling omnidirectional movement of the robot. Simultaneously, the development board 202 continuously receives data from the gyroscope and controls the servo motors 115 and the brushless DC motors 104 to maintain its balance. The front-facing camera 242 observes changes in the external environment, and the ultrasonic sensor 244, fixed below the front-facing camera 242, detects nearby obstacles, enabling timely avoidance of pedestrians or obstacles and controlling the robot to complete autonomous navigation.

Claims

1. A dual-wheel-legged end-of-arm logistics delivery robot, characterized in that, The dual-wheeled end-effector delivery robot includes a leg system (1) and a vehicle body (2); The outrigger linkage (1) is a parallel mechanism that forms a seven-bar linkage with the vehicle body (2). Two sets of three-bar linkages are symmetrically distributed. The two No. 2 rods (108) in each set of three-bar linkages are hinged together in the middle. The upper ends of the two No. 2 rods (108) are respectively hinged to the lower part of the No. 3 rod (112). The upper part of each No. 3 rod (112) is hinged to the shoulder (113) on the vehicle body via the main steering wheel through the servo motor (115). The outer side of the shoulder (113) is provided with a limiting ring (116) to limit the rotation angle of the No. 3 rod (112). The lower ends of the two No. 2 rods (108) are respectively hinged to the upper parts of the No. 1 rod (106) and the No. 4 rod (109). The lower part of the No. 1 rod (106) is fixedly connected to the outer ring of the bearing. The inner ring of the bearing is fixedly connected to the fixed bushing (105) of the brushless DC motor (104), and the lower part of the fourth rod (109) is fixed on the fixed bushing (105) of the brushless DC motor (104); the output shaft of the brushless DC motor (104) is connected to the wheel (117), so that the brushless DC motor (104) drives the wheel (117) to rotate; the middle parts of the first rod (106) and the fourth rod (109) are respectively hinged to one side of the support leg connecting rod (107), and the other side of the support leg connecting rod (107) is respectively connected to the upper part of the support leg (102), and the lower end of the support leg (102) is equipped with a guide wheel (101); the first rod (106) is limited and constrained by the baffle (103); A front-facing camera (242) is provided on the outer front side of the vehicle body. The front-facing camera (242) is mounted on a camera base (241) fixed to the vehicle body (2) by a camera bracket (243). An ultrasonic sensor (244) is fixed below the front-facing camera (242). A robotic arm (3) is provided inside the vehicle body. The robotic arm base (301) is connected to the first-stage arm (302) via a digital servo motor one (309). The first-stage arm (302) is connected to the second-stage arm (303) via a digital servo motor two (308). The second-stage arm (303) is connected to the output shaft (306) via a digital servo motor three (304). A camera (305) for recognizing the button positions and digital information of the elevator button panel (4) is connected to the robotic arm. The robotic arm control lever (307) is fixed on the upper and front of the output shaft (306); a laser radar transmitter (245) is provided on the upper rear of the vehicle body (2), which is driven to rotate by a DC motor (248) through a belt (246) and a pulley (247); the lower part of the robotic arm base (301) is a storage box, and the upper part of the storage box is provided with an ESC center board (201), a development board (202) and a Raspberry Pi development board (203), wherein the ESC center board (201) controls the rotation of the DC brushless motor (104); the development board (202) and the Raspberry Pi development board (203) communicate through a serial port, and the development board (202) controls the movement of the robotic arm control lever (307).

2. The dual-wheeled legged end-effector delivery robot according to claim 1, characterized in that, A limiting ball (110) is provided on the outer side of the hinge position in the middle of one of the two No. 2 rods (108). The limiting ball (110) corresponds to the limiting ball seat (114) at the bottom of the vehicle body (2). When the vehicle body (2) is lowered to the lowest position, the limiting ball (110) falls into the spherical seat of the limiting ball seat (114) to enhance the stability of the outrigger rod system (1).

3. The dual-wheeled legged end-effector delivery robot according to claim 1 or 2, characterized in that, The storage box is composed of a storage box bottom plate (207), a storage box side plate (205), a storage box cover plate (204), and a storage box rear side plate (206) which are fixedly connected by angle iron.

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