Telescopic landing leg type omnidirectional AMR for narrow roadway

Abstract

The invention relates to a telescopic landing leg type omnidirectional AMR for a narrow roadway, which is characterized in that a wheel train is arranged in a manner of combining a horizontal steering driving wheel with an auxiliary universal supporting wheel, and the omnidirectional AMR comprises the universal supporting wheel at the front part in the advancing direction and the steering driving wheel at the rear part in the advancing direction; the universal supporting wheels are distributed on the two sides of a center shaft of the vehicle body in pairs through first cross-shaped commutators, and the steering driving wheels are distributed on the two sides of the center shaft of the vehicle body in pairs through second cross-shaped commutators. The two universal supporting wheels and the two steering driving wheels are connected with each other through a telescopic device, so that internal and external stretching of the wheels is realized; lifting mechanisms are arranged at the two ends of a middle shaft of the vehicle body. According to the telescopic supporting leg type heavy-load AMR suitable for the narrow roadway scene, the vehicle body height of the AMR is reduced under the condition that the large load of the AMR is guaranteed, so that the gravity center height of carried goods is reduced, and the overturning risk is reduced.

Description

Technical Field

[0001] The present invention relates to the field of in-line warehousing logistics, and in particular to the logistics of heavy-loaded goods transported in narrow lanes. Background Art

[0002] A heavy-duty mobile robot (AGV / AMR) is a smart vehicle that is powered by batteries or internal combustion engines, equipped with high-power motors, reducers and steering devices to achieve flexible operation. It has functions such as speed regulation, opening and lowering compensation, vehicle braking, all-round steering, free path planning, automatic guidance, and online fast charging. It can also be centrally dispatched and managed.

[0003] In recent years, the navigation technology and control system of heavy-duty mobile robots have been developing towards diversification and flexibility. With the development of navigation technology and the reduction of application costs, the navigation method of heavy-duty mobile robots has been continuously developed from rails to QR codes, magnetic strips, lasers and vision, and chassis control has also developed towards servo control. A variety of navigation and control methods will be adopted according to the different characteristics and needs of users.

[0004] Unmanned transport robots are gradually replacing manual lifting and rail transportation. Compared with traditional methods, unmanned transport robots have the characteristics of high safety, high transportation efficiency and high transportation precision.

[0005] For heavy-loaded goods that need to be transported in narrow lanes, overhead cranes cannot enter narrow workshops and the accuracy of placing goods is low; using rail robots for transportation causes large vibrations, and the risk of goods falling from above is high, and complex grooving of the factory floor is required. The bottlenecks encountered when using existing backpack unmanned handling robots (AGV / AMR) are: heavy-loaded robots are large and tall, and the width of the robots cannot exceed the bracket, so the center of gravity of the goods is high, and narrow heavy-loaded robots face the risk of overturning when moving sideways; when operating in narrow spaces, the operation and parking accuracy requirements are very high, the laser vision navigation has low accuracy and is easy to collide with the wall, and the navigation methods such as magnetic strips and ribbons are designed for large-scale transportation, and the on-site deployment is complex. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present application designs a heavy-duty AMR with retractable legs suitable for narrow aisle scenarios, which ensures that when the AMR is carrying a large load, the body height of the AMR can be lowered to lower the center of gravity height of the carried cargo and reduce the risk of overturning.

[0007] The present invention provides an omnidirectional AMR with retractable legs in narrow lanes. The omnidirectional AMR adopts a wheel system in which a horizontal steering drive wheel is combined with an auxiliary universal support wheel, and the wheel system includes a universal support wheel at the front of the forward direction and a steering drive wheel at the rear of the forward direction; the universal support wheels are distributed in pairs on both sides of the center axis of the vehicle body through a first cross commutator, and the steering drive wheels are distributed in pairs on both sides of the center axis of the vehicle body through a second cross commutator; The two universal support wheels and the two steering drive wheels are connected to each other through a telescopic device to achieve the inward and outward telescopic movement of the wheels; and lifting mechanisms are arranged at both ends of the center axis of the vehicle body.

[0008] Furthermore, the lifting mechanism and the universal wheel telescopic mechanism adopt a linkage design, and mechanical synchronization is ensured through the form of a mechanical connecting rod-coupling between the lifters to realize the control of the lifting of the lifting device and the telescopic of the universal wheel; by configuring the reduction ratio of the transmission mechanism, the lifting and telescopic stroke and speed synchronization are realized.

[0009] Furthermore, the lifting mechanism includes two lifts and a guide mechanism, the two lifts are mechanically synchronized in the form of a mechanical link-coupling, and the lifting arm is vertically guided by a first guide rail slider mechanism.

[0010] As a preferred real-time solution of the present application, the lifting arm adopts a double slider mechanism to balance the eccentric moment caused by the overload of the lift.

[0011] Furthermore, the universal wheel telescopic mechanism includes a second guide rail slider mechanism and a ball screw mechanism, which are synchronized with the lifting stroke and speed through a reducer ratio.

[0012] As a preferred real-time solution of the present application, the coefficient of the relationship between the wheelbase and the wheelbase of the omnidirectional AMR is: .

[0013] The present application also provides a navigation method for the above-mentioned narrow lane retractable leg omnidirectional AMR, the method comprising the following steps: S1: Distribute two radars at both ends of the diagonal of the omnidirectional AMR; S2: The omnidirectional AMR starts at the initial position, and the two radars obtain their own initial positions according to the reflective mark at the starting point; S3: converting the position data of the second radar into the coordinate system of the first radar according to the conversion relationship set by the vehicle body size; S4: Take the point cloud of the first 180° of the first radar, take the converted point cloud data of the second 180° of the second radar, and fuse them into a point cloud image; S5: Positioning the omnidirectional AMR according to the fused point cloud image; S6: Based on the positioning, the omnidirectional AMR is navigated to the color ribbon by radar, and the switching point coordinates are set on the color ribbon according to the scene; S7: When the vehicle reaches the coordinates of the switching point, the front and rear color ribbon QR code sensors in the running direction both recognize the color ribbon signal, the radar navigation is paused, and the color ribbon QR code navigation mode is turned on; S8: After the ribbon QR code sensor recognizes the stop QR code on the ground, the omnidirectional AMR stops running and completes the ribbon QR code navigation.

[0014] Beneficial effects of the present invention: The present application provides an omnidirectional AMR with retractable legs in narrow aisles, which ensures that the height of the AMR body is reduced when the AMR is under a large load, so as to reduce the center of gravity height of the carried goods and reduce the risk of overturning. The width of the AMR can meet the requirements of walking on the bottom of a narrow bracket or in a narrow workshop. When operating in narrow aisles, the navigation tracking accuracy of the AMR needs to be less than ±10mm, which is necessary to ensure the high-precision tracking capability of the AMR in narrow aisles and reduce the complexity of navigation deployment in large scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the wheel system layout of the omnidirectional AMR with retractable legs in narrow aisles; Figure 2 It is a structural schematic diagram of the lifting and outrigger telescopic integrated mechanism in the embodiment; Figure 3 Schematic diagram of the lifting guide positioning cone pin in the embodiment; Figure 4 This is a diagram showing an implementation method of an AMR chassis in an embodiment; Figure 5 It is the force analysis diagram of AMR in the critical state of overturning; Figure 6 This is a schematic diagram of the scanning range during dual laser radar navigation; Figure 7 This is the overall architecture diagram of this application. DETAILED DESCRIPTION

[0016] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0017] The present invention provides an omnidirectional AMR with retractable legs in narrow lanes. The omnidirectional AMR adopts a wheel system in which a horizontal steering drive wheel is combined with an auxiliary universal support wheel, and the wheel system includes a universal support wheel at the front of the forward direction and a steering drive wheel at the rear of the forward direction; the universal support wheels are distributed in pairs on both sides of the center axis of the vehicle body through a first cross commutator, and the steering drive wheels are distributed in pairs on both sides of the center axis of the vehicle body through a second cross commutator; The two universal support wheels and the two steering drive wheels are connected to each other through a telescopic device to achieve the inward and outward telescopic movement of the wheels; and lifting mechanisms are arranged at both ends of the center axis of the vehicle body.

[0018] Furthermore, the lifting mechanism and the universal wheel telescopic mechanism adopt a linkage design, and mechanical synchronization is ensured through the form of a mechanical connecting rod-coupling between the lifters to realize the control of the lifting of the lifting device and the telescopic of the universal wheel; by configuring the reduction ratio of the transmission mechanism, the lifting and telescopic stroke and speed synchronization are realized.

[0019] Furthermore, the lifting mechanism includes two lifts and a guide mechanism, the two lifts are mechanically synchronized in the form of a mechanical link-coupling, and the lifting arm is vertically guided by a first guide rail slider mechanism.

[0020] As a preferred real-time solution of the present application, the lifting arm adopts a double slider mechanism to balance the eccentric moment caused by the overload of the lift.

[0021] Furthermore, the universal wheel telescopic mechanism includes a second guide rail slider mechanism and a ball screw mechanism, which are synchronized with the lifting stroke and speed through a reducer ratio.

[0022] Embodiment 1:

[0023] like Figure 1 As shown, the requirements provided in this application take the narrow aisle of 1200mm as an example, the cargo is 4t, the AMR weighs 2t, the AMR body width is designed to be 1000mm, and the vehicle length is required to be 4500mm. If there are only drive wheels, , the vehicle running stability is poor.

[0024] The chassis implementation plan is as follows: S1: Use horizontal steering drive wheel + auxiliary universal support wheel to arrange the wheel system, so that the coefficient of the relationship between the left and right wheel track B and the front and rear wheel wheelbase L; ,satisfy safety requirements, such as Figure 1 shown.

[0025] S2: Based on preliminary calculations of the AMR's own weight and cargo weight, a horizontal drive wheel with a single wheel load of up to 2000kg and a wheel diameter of 200mm is selected. A universal wheel with a rated load of 1500kg and a wheel diameter of 152mm is selected. After the wheel system is designed, the vehicle height is only 600mm, and the wheel system can adapt to an eccentric load of ±300mm for cargo.

[0026] S3: Calculate the support force of the universal wheel ,slope 3°, total load 6000kg, ground friction coefficient The total rated traction that the four driving steering wheels can provide is 0.02. is 5220N, satisfying the following relationship.

[0027] ; S4: Use retractable universal support wheels. When the AMR dives into the bottom of the bracket and cargo, in order to prevent interference with the cargo and bracket, the universal wheels are in a retracted state before it can smoothly enter the bracket. The lifting device is in a descending state at this time; during the docking process between the AMR and the cargo, the lifting device rises, the overall center of gravity of the AMR + cargo rises, the universal wheels are extended synchronously, and the coefficients of the wheelbase and wheelbase of the universal wheels are expanded to: ; The lifting mechanism and the universal wheel telescopic mechanism adopt a linkage design, and the lifting device lifting and universal wheel telescopic control are realized through the same set of drive control equipment. By configuring the reduction ratio of the transmission mechanism, the lifting device lifting and universal wheel telescopic speed can be kept consistent.

[0028] The lifting mechanism consists of two lifts and a guide mechanism. The lifting device mainly consists of two CS50 lifts and a guide mechanism. A single lift can provide a maximum lifting force of 50kN, and the selection leaves sufficient margin to deal with possible eccentric loads. The two lifts are mechanically synchronized in the form of a mechanical link-coupling to reduce eccentric loads caused by different lifting heights and protect the life of the lift. The lifting arm is guided vertically by a guide rail slider mechanism, and the double slider mechanism can effectively balance the eccentric moment caused by the eccentric load of the lift.

[0029] The universal wheel telescopic mechanism is mainly composed of a guide rail slider mechanism and a ball screw mechanism. The telescopic device is controlled by a ball screw and synchronized with the lifting stroke and speed through a reducer ratio. When performing a task, the on-board control software only needs to send a signal to the driver, and the driver controls the lift to execute.

[0030] S5: The lifting arm is guided in the vertical direction by the guide rail slider mechanism, and the double slider mechanism can effectively balance the eccentric moment caused by the eccentric load of the lift. The guide positioning cone pins for bracket positioning are installed on the lifting plane. The cone pins are distributed at the diagonal positions of the 3700mm×620mm rectangle (consistent with the position of the bracket pin hole), which can offset the positioning deviation within ±15mm between the bracket and the AGV.

[0031] S6: The telescopic device is mainly composed of a guide rail slider mechanism and a ball screw mechanism. The telescopic device is controlled by a ball screw, with a stroke of 150mm and a rated telescopic speed of 150mm / min. It can provide a maximum push-pull force of about 5450N, which is much greater than the force required for the telescopic and direction return of the universal wheel.

[0032] S7: AMR keeps the cargo (including the bracket) from overturning during the lateral movement. After analyzing the AMR operating conditions, it is known that when the AGV is fully loaded and in an emergency stop during the lateral movement, the risk of the vehicle overturning is the greatest. The force under the critical state of overturning is analyzed, such as Figure 5 shown.

[0033] In the figure, F is the inertia force in the emergency stop state. Taking point A as the base point, the overall force in this state is solved to obtain the inertia force F=24132N when the vehicle overturns. From the analysis of the vehicle's braking performance, it can be seen that the maximum inertia force of the vehicle during emergency braking is: The parameter design of the whole vehicle structure can ensure that it will not overturn during transportation.

[0034] AMR adopts dual navigation design, dual radar laser SLAM + ribbon QR code navigation composite navigation mode. AMR uses dual radar laser SLAM navigation when running on the main road. When AMR enters a narrow workshop and drills into a bracket, it switches to ribbon QR code navigation and positioning.

[0035] Embodiment 2:

[0036] Based on the narrow lane retractable leg omnidirectional AMR provided in Example 1, this embodiment provides a navigation implementation method thereof: S1: Two radars are located at two diagonal corners of the AMR. S2: The AMR starts at the initial position. Based on the reflective mark at the starting point, the two laser radars obtain their own initial positions.

[0037] S3: Convert the position data of the second radar to the coordinate system of the first radar according to the conversion relationship set by the vehicle body size. 4500mm, width The height difference between the two radars is 1000mm. The point feedback from the first radar is , the point feedback from the second radar is , the coordinates after the second radar conversion are .

[0038] S4: Take the first 180° point cloud of the first radar and the converted point cloud data of the second radar to form a point cloud map. The point cloud of the first 180° is The data set, the point cloud of the last 180° is For example, Figure 6 shown.

[0039] S5: Positioning is performed based on the fused 360° point cloud data of the dual radars.

[0040] S6: The AMR navigates to the ribbon through laser SLAM and sets the switching point coordinates in advance according to the scenario.

[0041] S7: When the machine reaches the switching point coordinates, the front and rear ribbon-QR code sensors in the running direction recognize the ribbon signal, the laser SLAM navigation is paused, and the ribbon-QR code navigation mode is turned on. If the switching coordinates are reached and the ribbon signal is not recognized, an error is reported.

[0042] S8: After the ribbon QR code sensor recognizes a stop QR code on the ground, the AMR stops running.

[0043] S9: When the AMR needs to return to laser navigation, it reaches the switching coordinate point, turns off the ribbon-QR code navigation mode, and turns on the laser SLAM navigation mode.

[0044] The combination of the AMR and its navigation method provided in the embodiment of the present application ensures that when the AMR is heavily loaded, the height of the AMR body is reduced to reduce the center of gravity height of the carried goods and reduce the risk of overturning. The width of the AMR can meet the requirements of walking on the bottom of a narrow bracket or a narrow workshop. When operating in a narrow channel, the navigation tracking accuracy of the AMR needs to be less than ±10mm, which is necessary to ensure the high-precision tracking capability of the AMR in narrow lanes and reduce the complexity of navigation deployment in large scenarios.

[0045] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A narrow lane retractable leg omnidirectional AMR, characterized in that: The omnidirectional AMR adopts a wheel system layout using a horizontal steering drive wheel combined with an auxiliary universal support wheel, including a universal support wheel at the front of the forward direction and a steering drive wheel at the rear of the forward direction; the universal support wheels are distributed in pairs on both sides of the center axis of the vehicle body through a first cross commutator, and the steering drive wheels are distributed in pairs on both sides of the center axis of the vehicle body through a second cross commutator; The two universal support wheels and the two steering drive wheels are connected to each other through a telescopic device to achieve the inward and outward telescopic movement of the wheels; Lifting mechanisms are arranged at both ends of the center axis of the vehicle body.

2. The narrow lane retractable leg omnidirectional AMR according to claim 1, characterized in that: The lifting mechanism and the universal wheel telescopic mechanism adopt a linkage design, and the mechanical synchronization is ensured by the mechanical connecting rod-coupling between the lifters to realize the control of the lifting device lifting and the telescopic of the universal wheel; by configuring the reduction ratio of the transmission mechanism, the lifting and telescopic stroke and speed synchronization are realized.

3. The narrow lane retractable leg omnidirectional AMR according to claim 2, characterized in that: The lifting mechanism comprises two lifts and a guide mechanism. Mechanical synchronization is ensured between the two lifts in the form of a mechanical link-coupling, and the lifting arm is guided in the vertical direction by a first guide rail slider mechanism.

4. The narrow lane retractable leg omnidirectional AMR according to claim 3, characterized in that: The lifting arm adopts a double slider mechanism to balance the eccentric moment caused by the overload of the lift.

5. The narrow lane retractable leg omnidirectional AMR according to claim 2, characterized in that: The universal wheel telescopic mechanism comprises a second guide rail slider mechanism and a ball screw mechanism, and is synchronized with the lifting stroke and speed through a reducer ratio.

6. The narrow lane retractable leg omnidirectional AMR according to claim 1, characterized in that: The coefficient of the relationship between the wheelbase and the wheelbase of the omnidirectional AMR is: .

7. A navigation method for a narrow lane with retractable legs and omnidirectional AMR according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: S1: Distribute two radars at both ends of the diagonal of the omnidirectional AMR; S2: The omnidirectional AMR starts at the initial position, and the two radars obtain their own initial positions according to the reflective mark at the starting point; S3: converting the position data of the second radar into the coordinate system of the first radar according to the conversion relationship set by the vehicle body size; S4: Take the point cloud of the first 180° of the first radar, take the converted point cloud data of the second 180° of the second radar, and fuse them into a point cloud image; S5: Positioning the omnidirectional AMR according to the fused point cloud image; S6: Based on the positioning, the omnidirectional AMR is navigated to the color ribbon by radar, and the switching point coordinates are set on the color ribbon according to the scene; S7: When the vehicle reaches the coordinates of the switching point, the front and rear color ribbon QR code sensors in the running direction both recognize the color ribbon signal, the radar navigation is paused, and the color ribbon QR code navigation mode is turned on; S8: After the ribbon QR code sensor recognizes the stop QR code on the ground, the omnidirectional AMR stops running and completes the ribbon QR code navigation.

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