A closed-loop collision protection method based on sling suspension steel wire rope angle detection

Abstract

The application discloses a kind of closed-loop collision protection methods based on sling suspension wire rope angle detection, comprising the following steps 1) potential meter is sampled to the displacement data of wire rope, calculate the displacement of x, y component;2) the displacement of x, y component is synthesized wire rope position vector, then the modulus of position vector is calculated after wire rope angle;3) whether the angle of wire rope is greater than collision safety threshold, if greater, then enter next step, otherwise enter step 1);4) corresponding translation mechanism is respectively zeroed to x, y axis direction angle reverse control processing;5) when suspension system is far away from the scene of collision accident, stop command is sent, otherwise enter step 4).The application uses potential meter to obtain the angle information of suspension wire rope in real time, can send movement command and stop command to the system, provides a protection measure and detection technology after collision, can avoid accident further expansion, with good economic benefit and feasibility.

Description

Technical Field

[0001] This invention relates to the field of sensing and application technology, and more specifically to a closed-loop collision protection method based on the detection of the angle of the suspended steel wire rope of the lifting device. Background Technology

[0002] In motion control systems (such as bridge cranes, gantry cranes, and tower cranes), the hook and the hoisted load often move horizontally in the x and y planes (horizontal planes). At this time, the operator needs to pay attention to the surrounding environment at all times. Any slight operational error or loss of focus will cause the hook or the hoisted load to collide with surrounding obstacles and stacked goods, which may seriously threaten the lives of the operators, on-site hookers, and on-site assembly personnel.

[0003] like Figure 1 The image shows a typical example of a collision where the takeoff height did not reach a safe height: (e.g.) Figure 1 As shown in the upper left, the bridge crane operates by hoisting goods from point A to a fixed point B. There is a stack of goods C between the two points. Figure 1 As shown in the upper right corner, during normal hoisting, the cargo is first raised from point A to a safe height and then moved towards point B. After reaching the vicinity of point B (after passing over the debris C), it can be lowered to the target placement point B. Figure 1 As shown in the lower left and lower right, when the lifting height is insufficient, the cargo will collide with cargo C when it is moved from point A to point B. In actual operation, this collision can also be caused by operating the translation mechanism before the heavy object leaves the ground, cargo being hooked to the ground by ropes, or cargo being actively pushed or pulled by humans.

[0004] Currently, commonly used collision avoidance methods such as lidar, dragon whisker sensors, and millimeter-wave radar all focus on collision prevention as a protection approach, aiming to stop the machine in time before a collision occurs to avoid accidents. However, there is little research on protection measures after a collision, and the failure of collision prevention may lead to further escalation of the accident.

[0005] Therefore, providing a collision protection method based on the angle detection of the suspended steel wire rope for active protection after a collision is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a closed-loop collision protection method based on the angle detection of the suspended wire rope of the lifting device. It is an active protection method after a collision occurs, which is a protection measure after a collision event occurs, and also a second layer of protection measure after the collision prevention fails.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A closed-loop collision protection method based on the detection of the angle of the suspended wire rope of the lifting device includes the following steps:

[0009] 1) The potentiometer samples the displacement data of the wire rope and calculates the displacement of the x and y components;

[0010] 2) Combine the displacements of the x and y components into a wire rope position vector, and then calculate the angle of the wire rope by taking the modulus of the position vector;

[0011] 3) Determine if the angle of the wire rope is greater than the collision safety threshold. If it is, proceed to the next step; otherwise, proceed to step 1).

[0012] 4) The reverse control corresponding translation mechanism performs zeroing of the angles in the x and y axes respectively;

[0013] 5) Issue a stop command once the suspension system is far from the scene of the collision; otherwise, proceed to step 4.

[0014] Furthermore, in step 1), the displacement of the x and y components is calculated as follows:

[0015] In a horizontal dual-axis motion coordinate system, the rightward motion direction in the xz plane is positive, and the angle between the translation mechanism and the x-direction is 0°; the rightward motion direction in the yz plane is also positive, and the angle between the translation mechanism and the y-direction is 0°. The x-axis displacement sampling potentiometer sensor is installed parallel to the xz plane and collinear with the sampling connection line; the y-axis displacement sampling potentiometer sensor is installed parallel to the yz plane and collinear with the sampling connection line. At this point, the displacement of the wire rope in the x-direction is... The displacement in the y direction is , Normalized to the distance from the fixed pulley in the xz plane to the sampling point of the wire rope. Normalized to the distance from the fixed pulley in the yz plane to the sampling point of the wire rope, at this time , The length of the steel wire rope from the fixed point to the sampling point is denoted as H;

[0016] When the steel wire rope is at rest and hanging naturally, the distance between the origin of the x-axis displacement and the origin of the y-axis displacement is... :

[0017] ;

[0018] When the steel wire rope is stationary and hanging naturally, the angle formed between the rope's travel and the X-axis displacement sampling point is... The angle between the wire rope travel and the Y-axis displacement sampling point is... ,but:

[0019]

[0020]

[0021] During normal operation, point A is the real-time sampling point for the wire rope, and point B is... The sampling distance from the starting point, point C is The angle between the sampling distance from the starting point and the line segment formed by points B and CA is... The angle between the line segment formed by points C and BA is :

[0022]

[0023]

[0024] Determine which quadrant the wire rope falls into by using biaxial sampling length:

[0025] Judgment condition that the real-time sampling point A of the wire rope falls in the first quadrant:

[0026]

[0027] Judgment condition that the real-time sampling point A of the steel wire rope falls in the second quadrant:

[0028]

[0029] Judgment condition that the real-time sampling point A of the wire rope falls in the third quadrant:

[0030]

[0031] Judgment condition that the real-time sampling point A of the steel wire rope falls in the fourth quadrant:

[0032]

[0033] When the translation mechanism moves only in one direction, then or This will remain unchanged. Extending this to the above quadrant judgment conditions, we get:

[0034] The expanded first quadrant judgment conditions are as follows:

[0035]

[0036] The extended second quadrant judgment conditions are as follows:

[0037]

[0038] The extended third quadrant judgment conditions are as follows:

[0039]

[0040] The extended fourth quadrant judgment conditions are as follows:

[0041]

[0042] Based on the quadrant selection algorithm, calculate the absolute offset along the two component directions, and let the relative parallel displacements of the X-axis and Y-axis be respectively... and Right now:

[0043] In the first quadrant:

[0044]

[0045] When in the second quadrant:

[0046]

[0047] When in the third quadrant:

[0048]

[0049] When in the fourth quadrant:

[0050] .

[0051] Furthermore, in step 2), by... and The origin displacement is obtained by synthesis. Combined with the length H of the wire rope from the fixed point to the sampling point, the cone angle of the wire rope is calculated. The specific method is as follows:

[0052] The distance from the rope sampling point to the static sampling origin is :

[0053] ;

[0054] The angle of swing of the wire rope along the vertical in space :

[0055] .

[0056] Furthermore, in step 3), let the collision detection angle be... If the collision activation time is T and the cumulative collision time variable is t, then if a collision is detected... If so, the collision timer starts, t begins to accumulate, and the following condition is determined: If true, proceed to step 4); if false, proceed to step 1). If this is not true, then reset timer t to zero and proceed to step 1.

[0057] Furthermore, when proceeding to steps 4) and 5), and Maintain real-time computation to provide the necessary real-time data for steps 4 and 5.

[0058] Furthermore, in step 4), the given speed of the X-axis translation mechanism is set to... The given speed of the Y-axis translation mechanism is Minimum execution speed is Let the speed, displacement direction, and component displacement of the running mechanism be positively correlated, and let the speed adjustment coefficient be K, then:

[0059]

[0060] .

[0061] Furthermore, in step 5), real-time judgment is performed. and Check if the value has been zeroed. If not, proceed to step 4. If the value has been zeroed, shut down the machine.

[0062] Therefore, this invention provides a closed-loop collision protection method based on the angle detection of the suspended wire rope of the lifting device. Compared with the prior art, the beneficial effects of this invention are: by using a potentiometer to obtain the angle information of the suspended wire rope in real time, it can issue movement commands and stop commands to the system, providing a protection measure and detection technology after a collision, which can prevent the accident from escalating further, and has good economic benefits and feasibility. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0064] Figure 1 The attached figure is a schematic diagram of the normal hoisting and collision hoisting paths provided by the present invention;

[0065] Figure 2 The attached figure is a schematic diagram of the abnormal collision and recovery provided by the present invention;

[0066] Figure 3 The attached figure is a schematic diagram of the sampling resistor distribution and spatial installation provided by the present invention;

[0067] Figure 4 The attached figure is a schematic diagram of the X-axis and Y-axis sampling rope lengths provided by the present invention;

[0068] Figure 5 The attached figure is a schematic diagram of the static sampling and dynamic sampling provided by the present invention projected onto the XY plane;

[0069] Figure 6The attached figure is a schematic diagram of dynamic four-quadrant sampling provided by the present invention;

[0070] Figure 7 The attached figure is a schematic diagram of dynamic sampling along the four-quadrant axis provided by the present invention;

[0071] Figure 8 The attached figure is a schematic diagram of the dynamic sampling projection and static sampling projection distance provided by the present invention;

[0072] Figure 9 The attached figure is a schematic diagram showing the angle between the stationary steel wire rope and the position of the steel wire rope after the collision provided by the present invention;

[0073] Figure 10 The attached figure is a flowchart of a closed-loop collision protection method based on the angle detection of the suspended steel wire rope provided by the present invention. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0075] like Figure 2-10 As shown in the figure, this invention discloses a closed-loop collision protection method based on the angle detection of the suspended wire rope of the lifting device, including the following steps:

[0076] 1) The potentiometer samples the displacement data of the wire rope 2 and calculates the displacement of the x and y components;

[0077] In the horizontal dual-axis motion coordinate system of the spatial coordinate system (i.e., the x and y directions), the rightward motion direction in the xz plane is positive, and the angle between the translation mechanism 3 (e.g., the trolley in a bridge crane) and the x-direction is 0°; the rightward motion direction in the yz plane is positive, and the angle between the translation mechanism 3 and the y-direction is 0°; in this embodiment, the potentiometer is a sampling lever potentiometer 1, such as... Figure 3 As shown in the left figure (a schematic diagram of the positional relationship between the XZ plane sampling rod potentiometer 1 and the steel wire rope 2), the x-axis displacement sampling potentiometer sensor is installed parallel to the xz plane and is collinear with the sampling connection line (i.e., the steel wire rope sampling point 5 is connected by a flexible wire, and after the direction is changed by the fixed pulley 4, it is connected to the sampling rod potentiometer 1, thereby realizing real-time sampling of the steel wire rope sampling point 5. It is worth noting that the sampling rod potentiometer 1 mentioned here and below is a spring-loaded sensor, which is necessary to achieve real-time sampling). Figure 3As shown in the right figure (a schematic diagram of the positional relationship between the YZ plane sampling rod potentiometer 1 and the steel wire rope 2), the y-axis displacement sampling potentiometer sensor is installed parallel to the yz plane and is collinear with the sampling connection line (i.e., the steel wire rope sampling point 5 is connected by a flexible wire, and after the direction is changed by the fixed pulley 4, it is connected to the sampling rod potentiometer 1, thereby realizing real-time sampling of the steel wire rope sampling point 5). At this time, the displacement of the sampling steel wire rope in the x direction is... The displacement in the y direction is (The measurement markings remain unchanged after the direction is changed in the following text), then the displacement of the wire rope is constant when there is no collision with the lifting device (i.e., under static natural vertical tension). For ease of calculation, this state is defined as follows: Normalized to the distance from the fixed pulley 4 in the xz plane to the sampling point 5 of the wire rope, Normalized to the distance from the fixed pulley 4 to the wire rope sampling point 5 in the yz plane, i.e., the distance sampled in the xy plane. Displacement includes, for example Figure 4 The length from fixed pulley 4 to sampling point 5 of the wire rope in the left figure, and Displacement includes, for example Figure 4 The length from fixed pulley 4 to sampling point 5 of the wire rope in the right figure is [length at this point]. , The length of the steel wire rope 2 from fixed point 6 to sampling point 5 is denoted as H;

[0078] When the steel wire rope is at rest and hanging naturally, the projection of the sampling point on the xy plane is as follows: Figure 5 As shown in the left figure, the distance between the origin of the x-axis displacement and the origin of the y-axis displacement is at this time. ,,Right now It is the distance between the two fixed pulleys of the sampling sensor between the two planes:

[0079] ;

[0080] When the steel wire rope is stationary and hanging naturally, the angle formed between the rope's travel and the X-axis displacement sampling point is... (That is, in this state, the fixed pulley of the X-axis sampling sensor is the angle origin, and the angle formed by the line L connecting the two fixed pulleys and the X-axis fixed pulley to the sampling point of the wire rope), such as Figure 5 Right corner A The angle between the wire rope travel and the Y-axis displacement sampling point (That is, in this state, the fixed pulley of the Y-axis sampling sensor is the angle origin, and the angle formed by the line L connecting the two fixed pulleys and the Y-axis fixed pulley to the sampling point of the wire rope), such as Figure 5 Right corner A ,but:

[0081]

[0082]

[0083] If the wire rope shifts and It will also change. The displacement of the wire rope is described in terms of the circumscribed cone shape with the fixed point of the wire rope as the reference point. Because the distance from the sampling point to the fixed point is usually very close and the displacement change of the sampling point is very small, the change of the z-axis can be ignored in this system.

[0084] Upon collision, the displacement of the steel cable will inevitably fall within the four quadrants of the model, such as... Figure 6 As shown, Figure 6 The upper right corner shows a diagram illustrating the condition when the index falls in the first quadrant. Figure 6 The top left is a diagram showing the condition when the index falls in the second quadrant. Figure 6 The bottom left is a diagram showing the condition when the index falls in the third quadrant. Figure 6 The bottom right corner shows a schematic diagram when the wire rope falls in the fourth quadrant. During normal operation, point A is the real-time sampling point for the wire rope, and point B is... The sampling distance starts from the point (i.e., the equivalent point of the fixed pulley), and point C is... The angle between the sampling distance from the starting point (i.e., the equivalent point of the fixed pulley) and the line segment formed by points B and CA is... The angle between the line segment formed by points C and BA is ::

[0085]

[0086]

[0087] Determine which quadrant the wire rope falls into by using biaxial sampling length:

[0088] Judgment condition that the real-time sampling point A of the wire rope falls in the first quadrant:

[0089]

[0090] Judgment condition that the real-time sampling point A of the steel wire rope falls in the second quadrant:

[0091]

[0092] Judgment condition that the real-time sampling point A of the wire rope falls in the third quadrant:

[0093]

[0094] Judgment condition that the real-time sampling point A of the steel wire rope falls in the fourth quadrant:

[0095]

[0096] When the translation mechanism moves only in one direction (e.g., the translation mechanism only moves along the X-axis, and the translation mechanism does not move), such as... Figure 7 (As shown in the lower left and upper right), then or It will remain unchanged. Extending this to the quadrant judgment conditions above, we get:

[0097] The expanded first quadrant judgment conditions are as follows:

[0098]

[0099] The extended second quadrant judgment conditions are as follows:

[0100]

[0101] The extended third quadrant judgment conditions are as follows:

[0102]

[0103] The extended fourth quadrant judgment conditions are as follows:

[0104]

[0105] Based on the quadrant selection algorithm, calculate the absolute offset along the two component directions, and let the relative parallel displacements of the X-axis and Y-axis be respectively... and ,Right now:

[0106] In the first quadrant:

[0107]

[0108] When in the second quadrant:

[0109]

[0110] When in the third quadrant:

[0111]

[0112] When in the fourth quadrant:

[0113] ;

[0114] Through the above steps, the displacement of the x and y components of the sampling point is finally obtained, that is... and ;

[0115] 2) Combine the displacements of the x and y components into a wire rope position vector, and then calculate the angle of the wire rope by taking the modulus of the position vector;

[0116] Through the and The origin displacement is obtained by synthesis, combined with the length H of the wire rope from the fixed point to the sampling point (e.g., Figure 4 As shown in the right figure (H), the specific method for calculating the cone angle of the wire rope is as follows:

[0117] The distance from the rope sampling point to the static sampling origin is ,like Figure 8 As shown in the diagram, from sampling point A to the stationary sampling point in the four quadrants, then... for:

[0118] ;

[0119] like Figure 9 As shown, at this time Let be the straight-line distance between the steel wire rope after any deflection and the original perpendicular steel wire rope, and be the angle of swing of the steel wire rope along the vertical line in space. :

[0120] ;

[0121] 3) Determine if the angle of the wire rope is greater than the collision safety threshold. If it is, proceed to the next step; otherwise, proceed to step 1).

[0122] Let the collision detection angle be If the collision activation time is T and the cumulative collision time variable is t, then if a collision is detected... If so, the collision timer starts, t begins to accumulate, and the following condition is determined: If true, proceed to step 4); if false, proceed to step 1). If this is not true, then reset timer t and proceed to step 1).

[0123] It is worth noting that when proceeding to steps 4) and 5), and Maintain real-time calculations;

[0124] Setting parameters The severity of system collisions should be considered. The smaller the value, the more sensitive the collision detection. When setting the parameter T, the normal swing period should be taken into account. If the rope length is short, T should be reduced appropriately. If the rope length is long, T should be increased appropriately to avoid misjudgment.

[0125] 4) Reverse control corresponds to the translation mechanism resetting the angles in the x and y axes to zero. For example, if a collision occurs while the translation mechanism is running in the forward direction, the sensor can detect and calculate the displacement components in real time. If the value is greater than 0, the translation mechanism should be controlled to move in the opposite direction of the collision.

[0126] Let the X-axis translation mechanism be given a speed of The given speed of the Y-axis translation mechanism is Minimum execution speed is Let the speed, displacement direction, and component displacement of the running mechanism be positively correlated, and let the speed adjustment coefficient be K, then:

[0127]

[0128] ;

[0129] Because the displacement of the x and y components at the sampling point (i.e. and The directions have the same sign, meaning the speed obtained from the above formula (introducing negative feedback in the control system) is the displacement of the x and y components of the sampling point after the given speed of the dual translation mechanism is executed (i.e., and The value of ) will gradually approach 0, that is, eventually return to the normal vertical suspension state before the collision;

[0130] 5) Issue a stop command once the suspension system is far from the scene of the collision; otherwise, proceed to step 4).

[0131] Real-time judgment and Check if the value has been zeroed. If not, proceed to step 4. If the value has been zeroed, shut down the machine.

[0132] like Figure 2 As shown in the upper left, when the goods are lifted from point A and moved to point B, an operator is near debris C. During the horizontal movement of the goods, the operator is caught between the goods and debris C. If the driver or other on-site operators notice this, they will immediately call the emergency stop button, but the operator will still be trapped between the goods and debris C. Figure 2 As shown in the upper right corner, under this working condition, even without an emergency stop, the present invention can actively restore the cargo to its pre-collision state by measuring the position of the wire rope, so that the compressed part returns to its pre-compression state. Ultimately, the cargo is only subjected to the lifting tension and does not compress any third party (e.g., Figure 2 (As shown in the image below).

[0133] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0134] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A closed-loop collision protection method based on the angle detection of the suspended wire rope of a lifting device, characterized in that, Includes the following steps: 1) The potentiometer samples the displacement data of the wire rope and calculates the displacement of the x and y components; 2) Combine the displacements of the x and y components into a wire rope position vector, and then calculate the angle of the wire rope by taking the modulus of the position vector; 3) Determine if the angle of the wire rope is greater than the collision safety threshold. If it is, proceed to the next step; otherwise, proceed to step 1). 4) The reverse control corresponding translation mechanism performs zeroing of the angles in the x and y axes respectively; 5) Issue a stop command once the suspension system is far from the scene of the collision; otherwise, proceed to step 4). In step 1), the displacement of the x and y direction components is calculated as follows: In the horizontal dual-axis motion coordinate system of the spatial coordinate system, the rightward motion direction in the xz plane is positive, and the angle between the translation mechanism and the x-direction is 0°; the rightward motion direction in the yz plane is positive, and the angle between the translation mechanism and the y-direction is 0°; the x-axis displacement sampling potentiometer sensor is installed parallel to the xz plane and collinear with the sampling connection line, and the y-axis displacement sampling potentiometer sensor is installed parallel to the yz plane and collinear with the sampling connection line. At this time, the displacement of the sampling wire rope in the x-direction is... The displacement in the y direction is , Normalized to the distance from the fixed pulley in the xz plane to the sampling point of the wire rope. Normalized to the distance from the fixed pulley in the yz plane to the sampling point of the wire rope, at this time , The length of the wire rope from the fixed point to the sampling point is denoted as H; When the steel wire rope is at rest and hanging naturally, the distance between the origin of the x-axis displacement and the origin of the y-axis displacement is... : ； When the steel wire rope is stationary and hanging naturally, the angle formed between the rope's travel and the X-axis displacement sampling point is... The angle between the wire rope travel and the Y-axis displacement sampling point is... ,but: During normal operation, point A is the real-time sampling point for the wire rope, and point B is... The sampling distance from the starting point, point C is The angle between the sampling distance from the starting point and the line segment formed by points B and CA is... The angle between the line segment formed by points C and BA is : Determine which quadrant the wire rope falls into by using biaxial sampling length: Judgment condition that the real-time sampling point A of the wire rope falls in the first quadrant: Judgment condition that the real-time sampling point A of the steel wire rope falls in the second quadrant: Judgment condition that the real-time sampling point A of the wire rope falls in the third quadrant: Judgment condition that the real-time sampling point A of the steel wire rope falls in the fourth quadrant: When the translation mechanism moves only in one direction, then or This will remain unchanged. Extending this to the above quadrant judgment conditions, we get: The expanded first quadrant judgment conditions are as follows: The extended second quadrant judgment conditions are as follows: The extended third quadrant judgment conditions are as follows: The extended fourth quadrant judgment conditions are as follows: Based on the quadrant selection algorithm, calculate the absolute offset along the two component directions, and let the relative parallel displacements of the X-axis and Y-axis be respectively... and Right now: When in the first quadrant: When in the second quadrant: When in the third quadrant: When in the fourth quadrant: ； In step 2), by... and The origin displacement is obtained by synthesis. Combined with the length H of the wire rope from the fixed point to the sampling point, the cone angle of the wire rope is calculated. The specific method is as follows: The distance from the rope sampling point to the static sampling origin is : ； The angle of swing of the wire rope along the vertical in space : ； In step 3), let the collision detection angle be... If the collision activation time is T and the cumulative collision time variable is t, then if a collision is detected... If so, the collision timer starts, t begins to accumulate, and the following condition is determined: If true, proceed to step 4); if false, proceed to step 1). If the condition is not met, then reset the timer t to zero and proceed to step 1). In step 4), the given speed of the X-axis translation mechanism is set to... The given speed of the Y-axis translation mechanism is Minimum execution speed is Let the speed, displacement direction, and component displacement of the running mechanism be positively correlated, and let the speed adjustment coefficient be K, then: ； In step 5), determine the real-time and Check if the value has been zeroed. If not, proceed to step 4. If the value has been zeroed, shut down the machine.

2. The closed-loop collision protection method based on the angle detection of the suspended wire rope of the lifting device according to claim 1, characterized in that, When proceeding to steps 4) and 5), and Maintain real-time calculations.

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