Fluid loading and unloading arm capable of automatically moving for tank car

Abstract

The invention relates to the technical field of fluid loading and unloading arms, in particular to a fluid loading and unloading arm for a tank truck capable of moving autonomously, which comprises a stand column, a gas-phase arm and a liquid-phase arm are mounted on the stand column, and each of the gas-phase arm and the liquid-phase arm consists of an inner arm, an outer arm, an overhanging arm and a liquid inlet pipeline; pipelines of the liquid inlet pipeline and the inner arm, the inner arm and the outer arm, and the outer arm and the overhanging arm are connected through rotating structures; the rotating structures are used for rotating motion among the inner arm, the outer arm and the overhanging arm; the inner arm comprises an inner arm rotating assembly and an inner arm steel pipe, and the inner arm rotating assembly is used for achieving transverse rotating motion of the inner arm steel pipe; the system drives the loading and unloading arm to autonomously move to be in butt joint with a tank car flange opening according to the flange circle center position coordinates provided by the flange positioning visual module, and manual butt joint operation can be replaced. The invention discloses an autonomous movement loading and unloading arm structure and a control system, and all driving mechanisms of a loading and unloading arm can be coordinated and matched to realize autonomous movement of any track of the tail end of the loading and unloading arm under the unified control of the control system.

Description

Technical Field

[0001] The invention relates to the technical field of tank trucks, in particular to a fluid loading and unloading arm for tank trucks which can move autonomously. Background Art

[0002] In my country, the main method of land transportation for oil, gas and other liquids is tank truck transportation. The loading and unloading of tank trucks is mainly carried out by connecting the loading and unloading arm (also called crane pipe) to the station tank pipeline equipment for fluid loading and unloading. The fluid loading and unloading arm for tank trucks is commonly known as a small crane pipe or a lower loading and unloading arm. Each small crane pipe is composed of components such as a column, a locking device, a swivel joint, a connecting pipe, a balance cylinder, and a breakaway valve. Structurally, it can be divided into four parts: a column, an inner arm, an outer arm, and an outrigger arm (or a vertical pipe). The loading and unloading arm has different uses, and the structure and number of swivel joints are also different. It is generally composed of 3-5 swivel joints and connecting pipes, valves, etc. When the loading and unloading arm has 5 swivel joints, its end can achieve 360° full space coverage. The traditional small crane pipe (loading and unloading arm) is manually operated, and is connected to the loading and unloading port of the tank truck by pushing, pulling, and rotating. First, connect the liquid inlet end of the loading and unloading arm column side to the tank equipment, then the operator manually pushes, pulls and rotates the loading and unloading arm to connect the extended arm end of the loading and unloading arm to the inlet and outlet flange of the tank truck. After the loading and unloading arm is tightened and there is no leakage, start the loading and unloading operation.

[0003] The fluid loading and unloading arm for tank trucks is formed with the degree of freedom around the axis by a rotating joint. 3-5 rotating joints are arranged vertically and staggered to form full track coverage in three-dimensional space. Traditional rotating joints cannot move autonomously and need to be pushed, pulled, and rotated by manpower, which will increase the number of personnel at the station and the workload of the staff. With the development of science and technology and the popularization of industrial automation applications, there is an increasing demand for tank truck bottom loading and unloading arms that can achieve autonomous movement. For this purpose, a fluid loading and unloading arm for tank trucks that can achieve autonomous movement is provided. Summary of the invention

[0004] The purpose of the present invention is to provide a fluid loading and unloading arm for a tank truck that can move autonomously in view of the defects of the prior art, so as to solve the problems raised by the above-mentioned background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a fluid loading and unloading arm for a tank truck capable of autonomous movement, comprising a column, a gas phase arm and a liquid phase arm being mounted on the column, the gas phase arm and the liquid phase arm both being composed of an inner arm, an outer arm, an outrigger arm and a liquid inlet pipe; the pipes of the liquid inlet pipe and the inner arm, the inner arm and the outer arm, and the outer arm and the outrigger arm are all connected through a rotating structure, and the rotating structure is used for the rotational movement between the inner arm, the outer arm and the outrigger arm;

[0006] The inner arm includes an inner arm rotating assembly and an inner arm steel pipe, and the inner arm rotating assembly is used to realize the lateral rotation movement of the inner arm steel pipe; the inner arm rotating assembly is composed of a rectangular tube, a first connecting steel plate, a first motor seat, a first motor, a first reducer, a first small gear, a first large gear, a first short radius right angle elbow, an oil inlet flange, and a first rotary joint;

[0007] The outer arm comprises an outer arm transverse rotation assembly, an outer arm longitudinal rotation assembly, a balancing cylinder device, and an outer arm steel pipe; the outer arm transverse rotation assembly is used to realize the transverse rotation movement of the outer arm steel pipe, and the outer arm longitudinal rotation assembly is used to realize the longitudinal rotation movement of the outer arm steel pipe; the inner arm steel pipe is connected to the outer arm steel pipe through a second short radius right angle elbow;

[0008] The outer arm transverse rotation assembly is composed of a rectangular tube, a second connecting steel plate, a second motor seat, a second reducer, a second motor, a second large gear, a second rotary joint, and a second small gear;

[0009] A third short radius right angle elbow is welded to one end of the outer arm steel pipe, and the third short radius right angle elbow is connected to the second short radius right angle elbow through a third rotary joint, and a first large blade is installed on the third rotary joint, and the first large blade is connected to the first connecting plate, and the first connecting plate is connected to the piston rod joint of the first hydraulic cylinder, and the first hydraulic cylinder is connected to the outer arm steel pipe through the first steel plate; the third rotary joint is connected to the outer arm steel pipe through a balancing cylinder device;

[0010] The other end of the outer arm steel pipe is connected to the fourth short radius right angle elbow through the outer arm rotating assembly, and the fourth short radius right angle elbow is connected to the outer arm through the fifth short radius right angle elbow. The outer arm is installed with a threaded breakaway valve and a welded ball valve;

[0011] The outrigger arm rotating assembly is composed of a fourth rotating joint, a second large blade, a second connecting plate, a second hydraulic cylinder, and a second steel plate.

[0012] As a preferred technical solution of the present invention, the inner arm steel pipe is connected to the first short radius right angle elbow through a first rotating joint, an oil inlet flange is welded at one end of the first short radius right angle elbow, a first large gear is welded on the first rotating joint, the first large gear is meshed with the first small gear on the first reducer, the first reducer and the first motor are both installed on the first motor seat, the first motor seat is fixedly connected to the first connecting steel plate, and the first connecting steel plate is fixedly connected to the rectangular tube.

[0013] As a preferred technical solution of the present invention, one end of the rectangular tube is tangent to the outer wall of the column and is fixed to the column by welding, and the other end of the rectangular tube is welded to the first connecting steel plate, and the main shaft of the first motor is connected to the gear in the first reducer; the first motor seat is connected to the first connecting steel plate by bolts and nuts.

[0014] As a preferred technical solution of the present invention, the rectangular tube is tangent to the inner arm steel tube and is fixed to the inner arm steel tube by welding. The side surface of the rectangular tube is welded to the second connecting steel plate. A second motor seat is installed on the second connecting steel plate by bolts. A second reducer is installed at the bottom of the second motor seat. A second motor is installed at the bottom of the second reducer. A second pinion is installed on the top output shaft of the second reducer. The second pinion is meshed and connected with the second large gear welded on the second rotary joint.

[0015] As a preferred technical solution of the present invention, the first steel plate is connected to the outer arm steel pipe by welding, and the cylinder bottom of the first hydraulic cylinder is connected to the first steel plate by bolts and nuts.

[0016] As a preferred technical solution of the present invention, a second large blade plate is installed on the fourth rotating joint, a second connecting plate is installed on the second large blade plate, the second connecting plate is connected to the piston rod joint of the second hydraulic cylinder, the end of the second hydraulic cylinder away from the piston rod is connected to the second steel plate, and the second steel plate is welded to the outrigger.

[0017] A control system for a fluid loading and unloading arm for a tank truck capable of autonomous movement, comprising a loading and unloading arm controller FPGA, wherein a human-machine interaction unit, a control unit, a signal acquisition and processing unit, and a visual interface unit are integrated on the loading and unloading arm controller FPGA;

[0018] The visual interface unit is connected to a visual processor, and the visual processor is connected to distance sensors such as cameras and lasers;

[0019] The signal acquisition and processing unit is used for homing detection, anti-collision detection, position detection, speed detection, and fault detection;

[0020] The human-computer interaction unit is connected to the buttons and touch screen on the control device;

[0021] The control unit is connected to the servo drive module, the hydraulic drive module and the loading and unloading arm valve group. The servo drive module is connected to the first motor on the first rotary joint, the second motor on the second rotary joint, and the servo motor on the automatic clamping claw; the hydraulic drive module is connected to the first hydraulic cylinder and the second hydraulic cylinder.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The invention discloses a lower loading and unloading arm system for a tank truck which can move autonomously. The system drives the loading and unloading arm to move autonomously and dock with the flange port of the tank truck according to the flange center position coordinates provided by a flange positioning vision module, thereby replacing manual docking operations.

[0024] The invention discloses an autonomous motion loading and unloading arm structure and a control system. Under the unified control of the control system, the driving mechanisms of the loading and unloading arm can coordinate and cooperate to realize the autonomous motion of any trajectory of the end of the loading and unloading arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 It is a schematic structural diagram of the inner arm rotating assembly of the present invention;

[0027] Figure 3 It is a schematic structural diagram of the outer arm transverse rotation assembly of the present invention;

[0028] Figure 4 It is a schematic structural diagram of the outer arm longitudinal rotation assembly of the present invention;

[0029] Figure 5 It is a schematic diagram of the connection structure of the outrigger arm of the present invention;

[0030] Figure 6 It is a control system module diagram of the present invention;

[0031] Figure 7 is a block diagram of a servo motor control system of the present invention;

[0032] Figure 8 It is a block diagram of the hydraulic cylinder control system of the present invention;

[0033] Fig. 9 It is a block diagram of the visual module of the loading and unloading arm control system of the present invention;

[0034] Fig.10 The coordinate system of the loading and unloading arm of the present invention has 5 rotating joints;

[0035] Fig.11 This is a diagram of the flange identification system of the present invention;

[0036] Fig.12 The figure is a flow chart of the flange identification system of the present invention.

[0037] In the figure: 1-column, 2-gas phase arm, 3-inner arm locking device, 4-liquid phase arm, 5-inner arm rotation assembly, 5-1-rectangular tube, 5-2-first connecting steel plate, 5-3-motor seat, 5-4-first motor, 5-5-first reducer, 5-6-first small gear, 5-7-first large gear, 5-8-first short radius right angle elbow, 5-9-oil inlet flange, 5-10-first rotary joint, 6-inner arm steel tube, 7-outer arm lateral rotation assembly, 7-1-rectangular tube, 7-2-second connecting steel plate, 7-3-second motor seat, 7-4-second reducer, 7-5-second motor, 7-6-second large gear, 7-7-second Rotating joint, 7-8-second small gear, 8-second short radius right angle elbow, 9-outer arm longitudinal rotation assembly, 9-1-third rotating joint, 9-2-first large knife plate, 9-3-first connecting plate, 9-4-first hydraulic cylinder, 9-5-first steel plate, 9-6-third short radius right angle elbow, 10-balancing cylinder device, 11-outer arm steel pipe, 12-extension arm rotating assembly, 12-1-fourth rotating joint, 12-2-second large knife plate, 12-3-second connecting plate, 12-4-second hydraulic cylinder, 12-5-second steel plate, 13-extension arm, 14-threaded break valve, 15-welded ball valve, 16-fourth short radius right angle elbow. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0039] Example: See Figure 1-5 The present invention provides a technical solution: a fluid loading and unloading arm for a tank truck capable of autonomous movement, comprising a column 1, on which a gas phase arm 2 and a liquid phase arm 4 are mounted, the gas phase arm 2 and the liquid phase arm 4 are both composed of an inner arm, an outer arm, an outrigger arm and a liquid inlet pipe; the pipes of the liquid inlet pipe and the inner arm, the inner arm and the outer arm, and the outer arm and the outrigger arm are all connected through a rotating structure, and the rotating structure is used for the rotational movement between the inner arm, the outer arm and the outrigger arm; the rotating structure is a rotating joint;

[0040] like Figure 2 As shown: the inner arm includes an inner arm rotating assembly 5 and an inner arm steel pipe 6, and the inner arm rotating assembly 5 is used to realize the lateral rotation movement of the inner arm steel pipe 6; the inner arm rotating assembly 5 is composed of a rectangular tube 5-1, a first connecting steel plate 5-2, a first motor seat 5-3, a first motor 5-4, a first reducer 5-5, a first small gear 5-6, a first large gear 5-7, a first short radius right angle elbow 5-8, an oil inlet flange 5-9, and a first rotary joint 5-10;

[0041] The inner arm steel pipe 6 is connected to the first short radius right angle elbow 5-8 through the first rotary joint 5-10, one end of the first short radius right angle elbow 5-8 is welded with an oil inlet flange 5-9, and the first rotary joint 5-10 is welded with a first large gear 5-7, the first large gear 5-7 is meshed with the first small gear 5-6 on the first reducer 5-5, the first reducer 5-5 and the first motor 5-4 are both installed on the first motor seat 5-3, the first motor seat 5-3 is fixedly connected to the first connecting steel plate 5-2, and the first connecting steel plate 5-2 is fixedly connected to the rectangular tube 5-1.

[0042] One end of the rectangular tube 5-1 is tangent to the outer wall of the column 1 and is fixed to the column 1 by welding, and the other end of the rectangular tube 5-1 is welded to the first connecting steel plate 5-2, and the main shaft of the first motor 5-4 is connected to the gear in the first reducer 5-5; the first motor seat 5-3 is connected to the first connecting steel plate 5-2 by bolts and nuts.

[0043] like Figure 3 As shown: the outer arm includes an outer arm transverse rotation assembly 7, an outer arm longitudinal rotation assembly 9, a balancing cylinder device 10, and an outer arm steel pipe 11; the outer arm transverse rotation assembly 7 is used to realize the transverse rotation movement of the outer arm steel pipe 11, and the outer arm longitudinal rotation assembly 9 is used to realize the longitudinal rotation movement of the outer arm steel pipe 11; the inner arm steel pipe 6 is connected to the outer arm steel pipe 11 through a second short radius right angle elbow 8;

[0044] The outer arm transverse rotation assembly 7 is composed of a rectangular tube 7-1, a second connecting steel plate 7-2, a second motor seat 7-3, a second reducer 7-4, a second motor 7-5, a second large gear 7-6, a second rotary joint 7-7, and a second small gear 7-8;

[0045] The rectangular tube 7-1 is tangent to the inner arm steel tube 6 and is fixed to the inner arm steel tube 6 by welding. The side of the rectangular tube 7-1 is welded to the second connecting steel plate 7-2. The second motor seat 7-3 is installed on the second connecting steel plate 7-2 by bolts. The second motor seat 7-3 is installed at the bottom of the second motor seat 7-3. The second motor 7-5 is installed at the bottom of the second reducer 7-4. The second pinion 7-8 is installed on the top output shaft of the second reducer 7-4. The second pinion 7-8 is meshed and connected with the second large gear 7-6 welded on the second rotary joint 7-7.

[0046] like Figure 4As shown: a third short radius right angle elbow 9-6 is welded to one end of the outer arm steel pipe 11, and the third short radius right angle elbow 9-6 is connected to the second short radius right angle elbow 8 through a third rotary joint 9-1, and a first large knife plate 9-2 is installed on the third rotary joint 9-1, and the first large knife plate 9-2 is connected to the first connecting plate 9-3, and the first connecting plate 9-3 is connected to the piston rod joint of the first hydraulic cylinder 9-4, and the first hydraulic cylinder 9-4 is connected to the outer arm steel pipe 11 through the first steel plate 9-5; the third rotary joint 9-1 is connected to the outer arm steel pipe 11 through the balancing cylinder device 10; the first steel plate 9-5 is welded to the outer arm steel pipe 11, and the cylinder bottom of the first hydraulic cylinder 9-4 is connected to the first steel plate 9-5 through bolts and nuts.

[0047] like Figure 5 As shown: the other end of the outer arm steel pipe 11 is connected to the fourth short radius right angle elbow 16 through the outer arm rotating assembly 12, the fourth short radius right angle elbow 16 is connected to the outer arm 13 through the fifth short radius right angle elbow, and the outer arm 13 is installed with a threaded breakaway valve 14 and a welded ball valve 15;

[0048] The outrigger arm rotating assembly 12 is composed of a fourth rotary joint 12-1, a second large blade plate 12-2, a second connecting plate 12-3, a second hydraulic cylinder 12-4, and a second steel plate 12-5. The second large blade plate 12-2 is mounted on the fourth rotary joint 12-1, the second large blade plate 12-2 is mounted on the second connecting plate 12-3, the second connecting plate 12-3 is connected to the piston rod joint of the second hydraulic cylinder 12-4, the end of the second hydraulic cylinder 12-4 away from the piston rod is connected to the second steel plate 12-5, and the second steel plate 12-5 is welded to the outrigger arm 13.

[0049] like Figure 6 As shown: A control system for a fluid loading and unloading arm for a tank truck capable of autonomous movement, comprising a loading and unloading arm controller FPGA, wherein a human-machine interaction unit, a control unit, a signal acquisition and processing unit, and a visual interface unit are integrated on the loading and unloading arm controller FPGA;

[0050] The visual interface unit is connected to the visual processor, and the visual processor is connected to distance sensors such as cameras and lasers;

[0051] The signal acquisition and processing unit is used for homing detection, anti-collision detection, position detection, speed detection, and fault detection;

[0052] The human-machine interaction unit is connected to the buttons and touch screen on the control device;

[0053] The control unit is connected to the servo drive module, the hydraulic drive module and the loading and unloading arm valve group. The servo drive module is connected to the first motor 5-4 on the first rotary joint 5-10, the second motor 7-5 on the second rotary joint 7-7, and the servo motor on the automatic clamping claw; the hydraulic drive module is connected to the first hydraulic cylinder 9-4 and the second hydraulic cylinder 12-4.

[0054] Working principle: A fluid loading and unloading arm for tank trucks that can move autonomously, such as Figure 1 As shown: it includes a gas phase arm 2 and a liquid phase arm 4, and the gas phase arm 2 and the liquid phase arm 4 are both composed of an inner arm, an outer arm, an outrigger arm and a liquid inlet pipe; the liquid inlet pipe and the inner arm, the inner arm and the outer arm, and the outer arm and the outrigger pipe are all connected through a rotating structure, and the rotating structure is used for the rotational movement between the inner arm, the outer arm and the outrigger arm;

[0055] like Figure 2 As shown: the lateral rotation of the inner arm is realized by the first motor 5-4 and the meshing gear pair in the inner arm rotating assembly. One end of the rectangular tube 5-1 is tangent to the outer wall of the column 1 and is fixed to the column by welding, and the other end is welded to the first steel plate 5-2; the first motor seat 5-3 is fixed to the first steel plate 5-2 by bolts and nuts; the first motor 5-4 is connected to the first reducer 5-5 by a coupling inside and fixed by bolts and nuts outside; the bottom of the first reducer 5-5 is connected to the first motor seat 5-3 by bolts and nuts. The first pinion 5-6 is connected to the output shaft of the first reducer 5-5 through a keyway, and the shaft end is punched, tapped and a baffle is added for axial limit; the first large gear 5-7 is welded to the outer wall of the first rotary joint 5-10. When the first motor 5-4 is running, the speed is reduced and the output torque is increased through the first reducer 5-5, driving the first pinion 5-6 on the output shaft of the reducer and the first large gear 5-7 meshing therewith to rotate. The oil inlet flange 5-9 and the first short radius right angle elbow 5-8 are fixed on the column 1 through some supporting parts; the first large gear 5-7 drives the first rotary joint 5-10 to rotate relative to the first short radius right angle elbow 5-8, thereby realizing the lateral movement of the inner arm.

[0056] like Figure 3As shown: the lateral rotation movement of the outer arm is realized by the second motor 7-5 in the outer arm lateral rotation assembly 7 and the meshing second large gear 7-6 and the second small gear 7-8; one end of the rectangular tube 7-1 is tangent to the inner arm steel tube 6, fixed to the inner arm steel tube 6 by welding, and the side is welded to the first steel plate 5-2. The second motor seat 7-3 is fixed to the second connecting steel plate 7-2 by bolts and nuts. The second motor 7-5 is connected to the second reducer 7-4 internally by a coupling and fixed externally with bolts and nuts. The bottom of the second reducer 7-4 is connected to the second motor seat 7-3 by bolts and nuts. The second small gear 7-8 is connected to the output shaft of the second reducer 7-4 through a keyway, and the shaft end is punched, tapped and a baffle is added for axial limitation. The second large gear 7-6 is welded to the outer wall of the second rotary joint 7-7. When the second motor 7-5 is working, the rotation speed is reduced and the output torque is increased through the second reducer 7-4, driving the second small gear 7-8 on the reducer output shaft and the second large gear 7-6 meshing therewith to rotate, and the second large gear 7-6 drives the second rotary joint 7-7 to rotate relative to the second short radius right-angle elbow 8, thereby realizing the lateral movement of the outer arm.

[0057] like Figure 4 As shown: the longitudinal rotation of the outer arm is realized by the first hydraulic cylinder 9-4, the first large blade plate 9-2 is fixed on the outer wall of the third rotary joint 9-1, and the piston rod joints on the first large blade plate 9-2 and the first connecting plate 9-3, the first connecting plate 9-3 and the first hydraulic cylinder 9-4 are all connected by bolts and nuts. One side of the first steel plate 9-5 is connected to the cylinder bottom of the first hydraulic cylinder 9-4 by bolts and nuts, and the other end is welded to the outer arm steel pipe 11. When the first hydraulic cylinder 9-4 is working, the extension and contraction of the piston rod drives the third short radius right angle elbow 9-6 to rotate relative to the third rotary joint 9-1 through the first large blade plate 9-2, realizing the longitudinal rotation of the outer arm. When the outer arm moves, the balance cylinder device 10 is used to balance the dead weight of the outer arm and the outrigger arm, which can make the arm flexible and light to operate and ensure the stability of the work.

[0058] like Figure 5As shown: the outrigger 13 comprises an outrigger rotating assembly 12, a threaded break valve 14 and a welded ball valve 15. The lateral rotation movement of the outrigger 13 is completed by the second hydraulic cylinder 12-4; the second large blade 12-2 is fixed on the outer wall of the fourth rotary joint 12-1, the second large blade 12-2 and the second steel plate 9-5, the second steel plate 9-5 and the second hydraulic cylinder 12-4 piston rod joint are connected by bolts and nuts, one end of the second steel plate 12-5 is connected to the bottom of the hydraulic cylinder by bolts and nuts, and the other end is welded to the outrigger 13. When the hydraulic cylinder is working, the extension and contraction of the piston rod drives the fourth short radius right angle elbow 16 to rotate relative to the fourth rotary joint 12-1 through the second large blade 12-2, thereby realizing the lateral rotation movement of the outrigger. During the operation of the loading and unloading arm, the outrigger rotating assembly 12 can also keep the outrigger in a horizontal position at all times. In addition, the outrigger 13 is also provided with a threaded break valve 14 and a welded ball valve 15; the threaded break valve 14 can prevent leakage accidents caused by accidental breakage of the pipeline; the welded ball valve 15 is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid regulation and control.

[0059] like Fig.10 Shown: Inverse kinematics calculation of loading and unloading arm:

[0060] The inverse kinematics calculation of the loading and unloading arm is the coordinates of the end of the loading and unloading arm (x r ,y r ,z r ) to the rotation angle (θ1, θ2, θ3, θ4, θ5) of the rotary joint.

[0061] The coordinate system layout of the five rotating joints of the loading and unloading arm is as follows: Fig.10 As shown, the Z axis is colinear with the axis of the rotary joint and points to the positive rotation direction; the common perpendicular line of the two adjacent axes, pointing to the direction of the next rotary joint, is the X axis; the Y axis is determined by the right-hand screw rule, O0 is the origin of the column coordinate system, and O1-O5 are the origins of the coordinate systems of the five rotary joints.

[0062] Table 1: DH parameters

[0063] Joint number <![CDATA[α i-1 ]]> <![CDATA[a i-1 ]]> <![CDATA[d i ]]> <![CDATA[θ i ]]> 1 <![CDATA[α0=0]]> <![CDATA[a1=l1]]> d1 <![CDATA[θ1]]> 2 <![CDATA[α1=0]]> <![CDATA[a2=l2]]> d2 <![CDATA[θ2]]> 3 <![CDATA[α2=90°]]> <![CDATA[a3=l3]]> d3 <![CDATA[θ3]]> 4 <![CDATA[α3=90°]]> <![CDATA[a4=l4]]> d4 <![CDATA[θ4]]> 5 <![CDATA[α4=90°]]> <![CDATA[a5=l5]]> d5 <![CDATA[θ5]]>

[0064] As shown in Table 1: l1 is the distance between the axis of the first rotary joint and the axis of the column; l2 is the distance between the axis of the second rotary joint and the axis of the first rotary joint; l3 is the distance between the axis of the third rotary joint and the axis of the second rotary joint; l4 is the distance between the axis of the fourth rotary joint and the axis of the third rotary joint; l5 is the distance between the axis of the fifth rotary joint and the axis of the fourth rotary joint;

[0065] d1 is the distance between the center point of the first rotary joint and the center point of the fixed coordinate system on the z-axis;

[0066] d2 is the distance on the z-axis between the center point of the second rotary joint and the center point of the first rotary joint;

[0067] d3 is the distance from the center point of the third rotary joint to the center point of the second rotary joint (i.e., the z-axis distance) projected on the axis of the second rotary joint;

[0068] d4 is the distance from the center point of the fourth rotary joint to the center point of the third rotary joint from the projection of the center point of the fourth rotary joint on the axis of the third rotary joint;

[0069] d5 is the distance from the center point of the fifth rotary joint projected on the axis of the fourth rotary joint to the center point of the fourth rotary joint (i.e., the z-axis distance);

[0070] according to Fig.10 Arrange the coordinate system, then the transformation matrix from coordinate system {i-1} to {i} for:

[0071]

[0072] They are rotations around the X axis α i-h , translate along the X axis a i-h , rotate about the Z axis by θ i , translate along the Z axis d i , coincide the coordinate systems {i-1} and {i}, that is

[0073]

[0074] in

[0075]

[0076] Then we get:

[0077]

[0078] Substitute the DH parameters in Table 1 into Find The transformation matrix from the end rotation joint pose to the fixed coordinate system is:

[0079]

[0080] The transformation matrix is ​​the rotation angle θ of each rotation joint h , θ2, θ3, θ4, θ5 are functions of the load and unload arm. If the end position of the load and unload arm is known, the rotation angle of each rotary joint can be calculated by analytical method.

[0081] The control system of the present invention comprises:

[0082] The control system consists of a host computer (visual processor Jetson Nano) and a slave computer (loading arm controller FPGA). The host computer Jetson Nano performs target flange identification, and the slave computer FPGA performs motion control.

[0083] (1) Host computer Jetson Nano;

[0084] In order to achieve fast and accurate recognition goals, this system uses Jetson Nano as the host computer. Jetson Nano is a powerful small computer that can run multiple neural networks, object detection, segmentation, speech processing and other applications in parallel. This system uses NIVIDIA Jetson Nano B01 as the motherboard. Jetson Nano is equipped with a quad-core ARM A57 processor, a 128-core MAXWELL GPU and 4GB LPDDR memory. It has sufficient AI computing power. Jetson Nano can apply real-time computer vision to various complex deep neural network (DNN) models and create a new AI project platform. Based on JetsonNano AI's computer vision, TensorFlow, Python, OpenCV, etc., these capabilities make multi-sensor robots, intelligent analysis equipment, and advanced artificial intelligence a reality. Complete NVIDIA JetPack TM The SDK contains acceleration libraries for deep learning, computer vision, graphics, multimedia, etc., which can help beginners get started quickly.

[0085] (2) Lower computer FPGA;

[0086] In view of the fact that Nano cannot emit PWM waves, FPGA is used when selecting the lower computer. FPGA control is more precise, the process is more intuitive and controllable, the circuit board is more stable, and the circuit system can be more solid. This system uses MLK_F3_CZ02-7020_7X FPGA, which uses ARM processor Cortex-A9, dual-core main frequency, equipped with DDR3 memory, data interface 16bit, single-chip memory size is 512MB, a total of two DDR3, a total of 1GB memory, data bandwidth 1066MHZ*32bits, maximum power consumption 7W, core board size 30mmx50mmx4.8mm, weight only about 10g, which is conducive to the design of a smaller functional baseboard; control system composition diagram Figure 6 shown.

[0087] The visual processing system of the present invention:

[0088] Flange recognition system, the tank truck flange recognition system mainly relies on the image recognition technology in the field of machine vision to realize its function. At present, the composition of machine vision can be mainly divided into two categories, the vision system based on industrial computers and the embedded intelligent vision system. Most of the existing products use embedded vision sensor solutions. This type of sensor uses the latest DSP, FPGA and large-capacity storage technology, and has the characteristics of easy use, easy maintenance, and easy installation. It can meet the application needs of various machine vision. The flange recognition system designed by the present invention adopts the Jetson Nano embedded intelligent vision system, and its structure is as follows Fig.11 shown.

[0089] In the design of the visual system, the light source is also a crucial link. It is an important part of machine vision. In terms of the light source installation method, the lighting source is installed at an angle behind the industrial camera. If it is directly behind, the camera will produce a shadow, which will affect the detection of the flange. The infrared laser is installed in the upper front of the camera, and the front will affect the camera's photography. Since the tank truck flange automatic positioning system usually works in a semi-open-air environment, natural light cannot guarantee sufficient light source all day long. When the light source cannot meet the requirements for obtaining the flange image, it will affect the final imaging effect and result in low imaging quality. Therefore, the first step after the flange recognition and positioning system is started is to determine the natural light source and decide whether to turn on the lighting source for supplementation; then it is necessary to determine whether to obtain a complete image of the flange. The initial positioning can only be completed after the flange is fully entered. After pre-processing the initial positioning image, accurate recognition is obtained through secondary positioning. The basic steps of the flange recognition system are as follows: Fig.12 As shown;

[0090] Figure 7 This is the block diagram of the servo motor control system. After the loading and unloading arm controller receives the solved rotation angle of the rotary joint, it transmits the data to the main control board FPGA controller. This loading and unloading arm motion control adopts PID control: PID (proportional, integral, differential) control is a control algorithm based on classical control theory to estimate past, present and future information. The PID control strategy has a simple structure, good stability, high reliability, and is easy to implement. It has great advantages in maturity and operability. The rotation angle of the rotary joint adopts a dual closed-loop PID control algorithm of speed closed loop and angle closed loop. Since the underlying motor drive control board directly receives the feedback speed of the motor, the real-time performance is better. Therefore, the speed closed-loop PID control algorithm is implemented in the underlying servo drive control board, and the FPGA main control board implements the angle PID control algorithm. The block diagram of the rotary joint angle dual closed-loop PID control algorithm is as follows Figure 7 shown.

[0091] Figure 8This is the block diagram of the hydraulic cylinder control system, which also uses double closed-loop PID control. The control algorithm block diagram is as follows Figure 8 shown.

[0092] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A fluid loading and unloading arm for a tank truck capable of autonomous movement, comprising a column (1), characterized in that: The column (1) is provided with a gas phase arm (2) and a liquid phase arm (4), each of which is composed of an inner arm, an outer arm, an outrigger arm and a liquid inlet pipe; the pipes of the liquid inlet pipe and the inner arm, the inner arm and the outer arm, and the outer arm and the outrigger arm are all connected via a rotating structure, and the rotating structure is used for the rotational movement between the inner arm, the outer arm and the outrigger arm; The inner arm comprises an inner arm rotating assembly (5) and an inner arm steel pipe (6), wherein the inner arm rotating assembly (5) is used to realize the lateral rotation movement of the inner arm steel pipe (6); the inner arm rotating assembly (5) is composed of a rectangular pipe (5-1), a first connecting steel plate (5-2), a first motor seat (5-3), a first motor (5-4), a first reducer (5-5), a first small gear (5-6), a first large gear (5-7), a first short radius right angle elbow (5-8), an oil inlet flange (5-9), and a first rotary joint (5-10); The outer arm comprises an outer arm transverse rotation assembly (7), an outer arm longitudinal rotation assembly (9), a balancing cylinder device (10), and an outer arm steel pipe (11); the outer arm transverse rotation assembly (7) is used to realize the transverse rotation movement of the outer arm steel pipe (11), and the outer arm longitudinal rotation assembly (9) is used to realize the longitudinal rotation movement of the outer arm steel pipe (11); the inner arm steel pipe (6) is connected to the outer arm steel pipe (11) via a second short radius right angle elbow (8); The outer arm transverse rotation assembly (7) is composed of a rectangular tube (7-1), a second connecting steel plate (7-2), a second motor seat (7-3), a second reducer (7-4), a second motor (7-5), a second large gear (7-6), a second rotary joint (7-7), and a second small gear (7-8); A third short radius right angle elbow (9-6) is welded to one end of the outer arm steel pipe (11); the third short radius right angle elbow (9-6) is connected to the second short radius right angle elbow (8) via a third rotating joint (9-1); a first large blade plate (9-2) is installed on the third rotating joint (9-1); the first large blade plate (9-2) is connected to a first connecting plate (9-3); the first connecting plate (9-3) is connected to a piston rod joint of a first hydraulic cylinder (9-4); the first hydraulic cylinder (9-4) is connected to the outer arm steel pipe (11) via a first steel plate (9-5); the third rotating joint (9-1) is connected to the outer arm steel pipe (11) via a balancing cylinder device (10); The other end of the outer arm steel pipe (11) is connected to a fourth short radius right angle elbow (16) through an outer arm rotating assembly (12), and the fourth short radius right angle elbow (16) is connected to the outer arm (13) through a fifth short radius right angle elbow, and a threaded breakaway valve (14) and a welded ball valve (15) are installed on the outer arm (13); The outrigger arm rotating assembly (12) is composed of a fourth rotating joint (12-1), a second large blade (12-2), a second connecting plate (12-3), a second hydraulic cylinder (12-4), and a second steel plate (12-5).

2. The fluid loading and unloading arm for a tank truck capable of autonomous movement according to claim 1, characterized in that: The inner arm steel pipe (6) is connected to the first short radius right angle elbow (5-8) through a first rotating joint (5-10); an oil inlet flange (5-9) is welded to one end of the first short radius right angle elbow (5-8); a first large gear (5-7) is welded to the first rotating joint (5-10); the first large gear (5-7) is meshed with a first small gear (5-6) on the first reducer (5-5); the first reducer (5-5) and the first motor (5-4) are both mounted on the first motor seat (5-3); the first motor seat (5-3) is fixedly connected to the first connecting steel plate (5-2); and the first connecting steel plate (5-2) is fixedly connected to the rectangular tube (5-1).

3. The fluid loading and unloading arm for a tank truck capable of autonomous movement according to claim 2, characterized in that: One end of the rectangular tube (5-1) is tangent to the outer wall of the column (1) and is fixed to the column (1) by welding; the other end of the rectangular tube (5-1) is welded to the first connecting steel plate (5-2); the main shaft of the first motor (5-4) is connected to the gear in the first reducer (5-5); and the first motor seat (5-3) is connected to the first connecting steel plate (5-2) by bolts and nuts.

4. The fluid loading and unloading arm for a tank truck capable of autonomous movement according to claim 1, characterized in that: The rectangular tube (7-1) is tangent to the inner arm steel tube (6) and is fixed to the inner arm steel tube (6) by welding. The side surface of the rectangular tube (7-1) is welded to the second connecting steel plate (7-2). The second connecting steel plate (7-2) is mounted with a second motor seat (7-3) by bolts. The bottom of the second motor seat (7-3) is mounted with a second reducer (7-4). The bottom of the second reducer (7-4) is mounted with a second motor (7-5). The top output shaft of the second reducer (7-4) is mounted with a second pinion (7-8). The second pinion (7-8) is meshed and connected with a second large gear (7-6) welded to the second rotary joint (7-7).

5. The fluid loading and unloading arm for a tank truck capable of autonomous movement according to claim 1, characterized in that: The first steel plate (9-5) is connected to the outer arm steel pipe (11) by welding, and the cylinder bottom of the first hydraulic cylinder (9-4) is connected to the first steel plate (9-5) by bolts and nuts.

6. The fluid loading and unloading arm for a tank truck capable of autonomous movement according to claim 1, characterized in that: The fourth rotary joint (12-1) is provided with a second large blade plate (12-2), the second large blade plate (12-2) is provided with a second connecting plate (12-3), the second connecting plate (12-3) is connected to the piston rod joint of the second hydraulic cylinder (12-4), the end of the second hydraulic cylinder (12-4) away from the piston rod is connected to the second steel plate (12-5), and the second steel plate (12-5) is welded to the outrigger arm (13).

7. A control system for a fluid loading and unloading arm for a tank truck capable of autonomous movement according to any one of claims 1 to 6, characterized in that: It includes a loading and unloading arm controller FPGA, on which a human-machine interaction unit, a control unit, a signal acquisition and processing unit, and a visual interface unit are integrated; The visual interface unit is connected to a visual processor, and the visual processor is connected to distance sensors such as cameras and lasers; The signal acquisition and processing unit is used for homing detection, anti-collision detection, position detection, speed detection, and fault detection; The human-computer interaction unit is connected to the buttons and touch screen on the control device; The control unit is connected to a servo drive module, a hydraulic drive module and a loading and unloading arm valve group; the servo drive module is connected to a first motor (5-4) on a first rotary joint (5-10), a second motor (7-5) on a second rotary joint (7-7) and a servo motor on an automatic clamping claw; the hydraulic drive module is connected to a first hydraulic cylinder (9-4) and a second hydraulic cylinder (12-4).

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