A crankshaft loading angle control system and control method

Abstract

This invention discloses a crankshaft loading angle control system and method. The crankshaft loading angle control system includes a frame, a loading mechanism, a positioning fixture, a vision detection module, an angle adjustment mechanism, and a control system. The loading mechanism is used to transport the crankshaft along a first direction. The positioning fixture is used to support the crankshaft. The vision detection module is used to acquire an image of the crankshaft located at the adjustment station and obtain the current loading angle. The angle adjustment mechanism is used to drive the crankshaft to rotate around its own axis. The control system is used to obtain the angle deviation based on the current loading angle and the target loading angle, and control the angle adjustment mechanism to drive the crankshaft to rotate based on the angle deviation. When the current loading angle of the crankshaft meets the preset allowable range, a material removal permission is output to the loading gantry. This invention can judge and adjust the circumferential loading angle of the crankshaft before the loading gantry removes the crankshaft, so that the circumferential posture of the crankshaft when entering the subsequent station meets the requirements for material removal and processing.

Description

Technical Field

[0001] This invention relates to the field of automated machining, and in particular to a crankshaft loading angle control system and control method. Background Technology

[0002] The crankshaft is a power transmission component in an engine, and its machining quality affects the engine's operating performance. As engine manufacturing moves towards automated processing, crankshaft machining production lines typically use loading mechanisms, robotic arms, or gantry equipment to sequentially feed the crankshafts to be processed into subsequent machining stations, thereby reducing manual handling and improving production continuity.

[0003] Multi-cylinder crankshafts differ from ordinary shaft parts in that they have multiple journals and eccentric parts distributed along the axial direction. Before entering the machining station, the workpiece needs to be in a specified loading position and at a specified circumferential loading angle. If the crankshaft's circumferential posture is inconsistent with the subsequent clamping, positioning, or machining requirements, it will affect the robot's gripping, machine tool clamping, and subsequent machining processes.

[0004] Existing crankshaft loading equipment typically uses a hopper, conveying mechanism, and positioning detection element to sequentially transport crankshafts, which are then picked up by a robot or gantry after reaching the loading position. However, this type of equipment mainly controls the conveying position of the crankshaft, making it difficult to determine and adjust the current circumferential loading angle of the crankshaft to the target loading angle before the gantry picks it up. This results in inconsistent postures when multi-cylinder crankshafts enter subsequent processing stations. Summary of the Invention

[0005] In view of the above, it is necessary to provide a crankshaft loading angle control system and control method to solve the problem that existing crankshaft loading equipment is unable to determine and adjust the current circumferential loading angle of the crankshaft to the target loading angle before the loading gantry removes the crankshaft.

[0006] To achieve the above objectives, the present invention provides a crankshaft loading angle control system for adjusting the loading angle of the crankshaft before the loading gantry removes the crankshaft, comprising a frame, a loading mechanism, a positioning fixture, a vision inspection module, an angle adjustment mechanism, and a control system.

[0007] The feeding mechanism is located on the frame and is used to convey the crankshaft along the first direction;

[0008] The positioning fixture is installed on the feeding mechanism to support the crankshaft;

[0009] The vision inspection module is used to acquire an image of the crankshaft located at the control station and to obtain the current loading angle of the crankshaft based on the image;

[0010] The angle adjustment mechanism is used to drive the crankshaft to rotate around its own axis;

[0011] The control system is coupled to the feeding mechanism, the vision inspection module, and the angle adjustment mechanism. It controls the feeding mechanism to move the positioning fixture carrying the crankshaft to the adjustment station, controls the vision inspection module to acquire an image of the crankshaft located at the adjustment station, and obtains the current feeding angle of the crankshaft based on the image. It obtains the angle deviation based on the current feeding angle and the target feeding angle, and controls the angle adjustment mechanism to rotate the crankshaft based on the angle deviation so that the current feeding angle of the crankshaft approaches or reaches the target feeding angle. When the current feeding angle of the crankshaft meets the preset allowable range, it outputs a material picking permission to the feeding gantry.

[0012] In some embodiments, the feeding mechanism includes a drive component, a drive sprocket, a driven sprocket, and a chain;

[0013] The drive unit is mounted on the frame, the drive sprocket is connected to the drive unit for transmission, the driven sprocket is spaced apart from the drive sprocket, and the chain is wound around the drive sprocket and the driven sprocket;

[0014] The positioning fixtures are multiple and are spaced apart on the chain along the first direction. The driving component is used to drive the chain to move through the drive sprocket, so that the multiple positioning fixtures move sequentially along the first direction.

[0015] The positioning fixture includes a positioning base plate, two support seats and a shaft end limiting block. The positioning base plate is connected to the chain, the two support seats are located on the positioning base plate and are used to support the journals of the crankshaft respectively, and the shaft end limiting block is located on the positioning base plate and is used to limit the crankshaft to move axially.

[0016] In some embodiments, the support base is provided with a V-shaped support opening for supporting the crankshaft;

[0017] The positioning base plate has multiple sets of mounting holes arranged at intervals along the first direction. Two support seats are connected to the positioning base plate through different sets of mounting holes to adjust the distance between the two support seats.

[0018] In some embodiments, the visual inspection module includes an industrial camera and an image processing unit;

[0019] Industrial cameras are used to acquire images of the crankshaft;

[0020] The image processing unit is coupled to an industrial camera to extract crankshaft features from the image of the crankshaft and to obtain the current loading angle of the crankshaft based on the crankshaft features;

[0021] The crankshaft features include main journal features and eccentric part features. The image processing unit is used to determine the main axis of the crankshaft based on the main journal features and to obtain the current loading angle based on the orientation relationship of the eccentric part features relative to the main axis.

[0022] The eccentric features include at least one of the following: connecting rod journal center, connecting rod journal profile, crank edge, and end reference.

[0023] In some embodiments, the crankshaft is a multi-cylinder crankshaft, and the image processing unit is further configured to acquire the image positions of at least two connecting rod journals and compare the phase relationship between the at least two connecting rod journals with pre-stored phase data;

[0024] The control system is also used to prohibit the output of material handling permission to the upward truss when the phase relationship does not meet the range corresponding to the pre-stored phase data.

[0025] In some embodiments, the angle adjustment mechanism includes two vertical frames, two tapered positioning shafts, a feed component, and a servo drive component;

[0026] Two vertical frames are located on either side of the control station;

[0027] Two tapered positioning shafts are respectively installed on two vertical frames and are used to insert into the center holes at both ends of the crankshaft to clamp the crankshaft; the shaft end limiting block is provided with a clearance part, which is arranged opposite to the center hole at the end of the crankshaft to avoid the tapered positioning shaft when it is inserted into the center hole;

[0028] The feed element is connected to the tapered positioning shaft and is used to move the tapered positioning shaft closer to or away from the end of the crankshaft;

[0029] The servo drive is connected to at least one tapered positioning shaft for driving the tapered positioning shaft and the crankshaft held by the tapered positioning shaft to rotate.

[0030] In some embodiments, the control system is further configured to control the vision detection module to acquire an image of the crankshaft again after the angle adjustment mechanism drives the crankshaft to rotate, obtain a verification feeding angle based on the re-acquired image, obtain a verification deviation based on the verification feeding angle and the target feeding angle, output a material picking permission to the feeding truss when the verification deviation is within a preset allowable range, and continue to control the angle adjustment mechanism to drive the crankshaft to rotate when the verification deviation exceeds the preset allowable range, or output an abnormal signal and prohibit the output of a material picking permission to the feeding truss.

[0031] In some embodiments, the control system is further configured to control the angle adjustment mechanism to rotate the crankshaft at a first speed when the angle deviation is greater than a first threshold, and to control the angle adjustment mechanism to rotate the crankshaft at a second speed when the angle deviation is less than or equal to the first threshold and greater than a second threshold, wherein the second speed is less than the first speed. The vision detection module is further configured to output a recognition confidence score, and the control system is further configured to control the angle adjustment mechanism to rotate the crankshaft at a predetermined trial angle when the recognition confidence score is lower than a preset value, and to control the vision detection module to acquire an image of the crankshaft again.

[0032] In some embodiments, the control system stores identification templates, target loading angles, allowable angle errors, and servo control parameters corresponding to multiple crankshaft models;

[0033] The control system is also used to call the corresponding identification template, target loading angle, allowable angle error, and servo control parameters according to the current crankshaft model. The crankshaft loading angle control system also includes a model acquisition component, which is coupled to the control system and is used to acquire the current crankshaft model. The model acquisition component includes at least one of a barcode scanner, a tooling identification sensor, a manual input unit, and a host computer communication unit.

[0034] The present invention also provides a crankshaft loading angle control method for adjusting the crankshaft loading angle before the loading truss removes the crankshaft, comprising:

[0035] The feeding mechanism transports the crankshaft positioned on the positioning fixture;

[0036] After the feeding mechanism delivers the crankshaft to the control station, the vision inspection module acquires an image of the crankshaft; the main axis of the crankshaft is determined based on the image.

[0037] Based on the image of the crankshaft, at least one off-center feature is determined, which includes at least one of the following: connecting rod journal center, connecting rod journal profile, crank edge, and end reference.

[0038] Based on the orientation relationship of the eccentric part relative to the main axis, the current loading angle of the crankshaft is obtained;

[0039] The angle deviation is obtained based on the current feeding angle and the target feeding angle.

[0040] Based on the angle deviation, the angle adjustment mechanism drives the crankshaft to rotate around its own axis so that the current feeding angle of the crankshaft is close to or reaches the target feeding angle.

[0041] After the angle adjustment mechanism drives the crankshaft to rotate, the vision detection module acquires an image of the crankshaft again;

[0042] The verification feeding angle is obtained from the re-acquired image, and the verification deviation is obtained from the verification feeding angle and the target feeding angle.

[0043] When the deviation is within the preset allowable range, the material handling permission is issued to the material handling truss.

[0044] The crankshaft loading angle control system and method provided by this invention transports the crankshaft, mounted on a positioning fixture, to the adjustment station via a loading mechanism. A vision detection module acquires an image of the crankshaft and obtains the current loading angle. The control system calculates the angle deviation based on the current loading angle and the target loading angle, and controls the angle adjustment mechanism to rotate the crankshaft around its own axis. Once the current loading angle of the crankshaft meets the preset allowable range, a material removal permit is issued to the loading gantry. Thus, the crankshaft can complete the loading angle adjustment before being removed by the loading gantry, ensuring that the circumferential posture of the crankshaft when entering the subsequent station meets the requirements for material removal and processing. Attached Figure Description

[0045] To more clearly illustrate the technical content 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.

[0046] Figure 1 This is a front view of the crankshaft loading angle control system provided in an embodiment of the present invention;

[0047] Figure 2 A top view of the crankshaft loading angle control system provided in an embodiment of the present invention;

[0048] Figure 3 for Figure 1 Enlarged schematic diagram of some of the structures in the diagram;

[0049] Figure 4 This is a schematic diagram of the positioning fixture provided in an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of the angle adjustment mechanism for clamping the crankshaft provided in an embodiment of the present invention;

[0051] Figure 6 This is a flowchart illustrating the crankshaft loading angle control method provided in an embodiment of the present invention.

[0052] Explanation of reference numerals in the attached figures:

[0053] 10. Rack;

[0054] 20. Feeding mechanism; 21. Drive component; 22. Drive sprocket; 23. Chain;

[0055] 30. Positioning fixture; 31. Positioning base plate; 32. Support seat; 33. Shaft end limit block;

[0056] 40. Visual inspection module;

[0057] 50. Angle adjustment mechanism; 51. Vertical frame; 52. Tapered positioning shaft; 53. Feed component; 54. Servo drive component;

[0058] 60. Control system;

[0059] 70. Sensor assembly; 71. First sensor; 72. Second sensor;

[0060] 80. Crankshaft;

[0061] 90. Loading truss. Detailed Implementation

[0062] The technical content of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0063] In this specification, relational terms such as "first" and "second" are used only to distinguish one entity from another, and do not necessarily require or imply such an actual relationship or order between these entities. The term "first direction" as used herein can be understood as the conveying direction of the crankshaft on the feeding mechanism 20. The term "second direction" as used herein can be understood as the direction intersecting the first direction. The term "axis of the crankshaft" as used herein can be understood as the axis of the main journals of the crankshaft 80 or an axial reference line defined by a plurality of main journals.

[0064] Please see Figures 1 to 5 This embodiment provides a crankshaft loading angle control system, which is used to adjust the loading angle of the crankshaft 80 before the loading truss 90 removes the crankshaft 80. The crankshaft loading angle control system includes a frame 10, a loading mechanism 20, a positioning fixture 30, a vision detection module 40, an angle adjustment mechanism 50, and a control system 60. The frame 10 supports at least some components of the loading mechanism 20, the positioning fixture 30, the vision detection module 40, the angle adjustment mechanism 50, and the control system 60. The loading mechanism 20 is located on the frame 10 and is used to transport the crankshaft 80 along a first direction. The positioning fixture 30 is located on the loading mechanism 20 and is used to support the crankshaft 80. The vision detection module 40 is used to acquire an image of the crankshaft 80 located at the adjustment station and to obtain the current loading angle of the crankshaft 80 based on the image. The angle adjustment mechanism 50 is used to drive the crankshaft 80 to rotate around its own axis. The control system 60 is coupled to the feeding mechanism 20, the vision inspection module 40 and the angle adjustment mechanism 50, and is used to control the feeding mechanism 20, the vision inspection module 40 and the angle adjustment mechanism 50 to perform corresponding actions.

[0065] In this embodiment, the control system 60 can first determine the crankshaft positioning status, crankshaft model status, visual recognition status, and angle adjustment mechanism status. The crankshaft positioning status can be acquired by the second sensor 72 located at the adjustment station. The crankshaft model status can be acquired by the model acquisition component. The visual recognition status can be output by the image processing unit. The angle adjustment mechanism status can be obtained by the positioning detection component of the tapered positioning shaft 52, the positioning signal of the feed component 53, and the feedback signal of the servo drive component 54. When all the above states meet the corresponding conditions, the control system 60 allows the angle adjustment mechanism 50 to perform clamping and rotation actions.

[0066] Please see Figure 1 and Figure 2 In this embodiment, the feeding mechanism 20 includes a driving component 21, a driving sprocket 22, a driven sprocket, and a chain 23. The driving component 21 is mounted on the frame 10. The driving sprocket 22 is connected to the driving component 21. The driven sprocket is spaced apart from the driving sprocket 22. The chain 23 is wound around the driving sprocket 22 and the driven sprocket. The driving component 21 can be a motor, a motor with a reducer, or other power component capable of driving the driving sprocket 22 to rotate. The driving component 21 drives the driving sprocket 22 to rotate, the driving sprocket 22 drives the chain 23 to move along a first direction, and the chain 23 drives the positioning fixture 30 and the crankshaft 80 on the positioning fixture 30 to move along the first direction.

[0067] In some embodiments, the chain 23 may include two conveyor chains spaced apart along a second direction, with the positioning fixture 30 spanning the two conveyor chains. The two conveyor chains may be driven by the same drive member 21 or connected by a synchronous transmission member to maintain synchronous movement. When the positioning fixture 30 spans the two conveyor chains, the crankshaft 80 can move along the first direction with the positioning fixture 30 and maintain its relative position during movement. Multiple positioning fixtures 30 are spaced apart along the first direction on the chain 23, allowing multiple crankshafts 80 to sequentially enter the control station at predetermined intervals.

[0068] In some embodiments, the feeding mechanism 20 further includes a conveying position detection element. The conveying position detection element can be an encoder, proximity switch, photoelectric sensor, or stroke detection element. The control system 60 can determine whether the positioning fixture 30 has reached the control station based on the detection result of the conveying position detection element. When the chain 23 moves to a preset distance before the control station, the control system 60 controls the drive component 21 to run at a first conveying speed; when the chain 23 moves near the control station, the control system 60 controls the drive component 21 to run at a second conveying speed, which is less than the first conveying speed; when the control station arrival detection element detects that the crankshaft 80 has arrived, the control system 60 controls the drive component 21 to stop. Through the above control method, the feeding mechanism 20 can convey the crankshaft 80 to the control station in a segmented conveying manner.

[0069] In some embodiments, the control system 60 can also compare the movement distance of the chain 23 with the detection result of the adjustment station positioning detection element. When the chain 23 has reached the predetermined movement distance but the adjustment station positioning detection element does not detect the crankshaft 80, the control system 60 can determine that the crankshaft is missing or the positioning fixture is unloaded. When the adjustment station positioning detection element detects the crankshaft 80 but the movement distance of the chain 23 has not reached the predetermined distance, the control system 60 can determine that the crankshaft placement position is abnormal or the positioning fixture position is abnormal, and output an abnormal signal.

[0070] Please see Figure 3 and Figure 4 In this embodiment, the positioning fixture 30 includes a positioning base plate 31, two support seats 32, and a shaft end limiting block 33. The positioning base plate 31 is connected to the chain 23, and the two support seats 32 are disposed on the positioning base plate 31 and are used to support the journals of the crankshaft 80 respectively. The shaft end limiting block 33 is disposed on the positioning base plate 31 and is used to limit the axial movement of the crankshaft 80. The positioning base plate 31 can be a single plate, or it can include a mounting plate connected to the chain 23 and a bearing plate located on the mounting plate. The support seats 32 can be connected to the positioning base plate 31 by bolts, pins, or other connecting parts. The shaft end limiting block 33 can be disposed at one end of the crankshaft 80 or at both ends of the crankshaft 80.

[0071] In some embodiments, the support base 32 is provided with a V-shaped support opening for supporting the crankshaft 80. After the crankshaft 80 is placed in the V-shaped support opening, the support base 32 can provide support for the journal of the crankshaft 80. The positioning base plate 31 is provided with multiple sets of mounting holes spaced apart along a first direction, and the two support bases 32 are connected to the positioning base plate 31 through different sets of mounting holes. Thus, when changing crankshafts 80 of different lengths, the support bases 32 can be connected to different sets of mounting holes, thereby changing the distance between the two support bases 32. The support base 32 may also be provided with an arc-shaped support opening or a support opening formed by two opposing support surfaces, as long as it can support the journal of the crankshaft 80.

[0072] In some embodiments, the positioning substrate 31 is further provided with a tooling identification unit. The tooling identification unit can be a QR code, barcode, RFID tag, magnetic tag, hole combination, or color identification mark. The model acquisition unit can read the tooling identification unit to obtain the crankshaft model corresponding to the current positioning tooling 30. The control system 60 calls the corresponding identification template, target loading angle, allowable angle error, and servo control parameters according to the crankshaft model corresponding to the current positioning tooling 30.

[0073] In some embodiments, a replaceable pad is provided between the support base 32 and the positioning base plate 31. The thickness of the replaceable pad is related to the journal diameter of the crankshaft 80. For crankshafts 80 with different diameters, replaceable pads of different thicknesses can be used to keep the main axis of the crankshaft 80 within a preset height range at the adjustment station. The control system 60 can also determine whether the current support height matches the crankshaft model based on the crankshaft model. When the crankshaft model corresponding to the tooling identification unit is inconsistent with the crankshaft model issued by the host computer, the control system 60 prohibits the angle adjustment mechanism 50 from clamping the crankshaft 80 and outputs an abnormal signal.

[0074] Please see Figure 3 and Figure 4 In this embodiment, the shaft end limiting block 33 is used to restrict the axial movement of the crankshaft 80. To ensure that the shaft end limiting block 33 does not interfere with the angle adjustment mechanism 50's contact with the crankshaft end, the shaft end limiting block 33 is provided with a clearance portion. The clearance portion is disposed opposite to the center hole of the crankshaft end to allow the tapered positioning shaft 52 to pass through or avoid the center hole when it is inserted. The clearance portion can be a through hole, a notch, a groove, or other structure that allows the tapered positioning shaft 52 to pass through or avoid. The shaft end limiting block 33 can abut against a non-central area of ​​the crankshaft end or a shoulder area of ​​the crankshaft end, placing the center hole of the crankshaft end in a position where the tapered positioning shaft 52 can enter. Thus, when the crankshaft 80 is conveyed along the first direction, the shaft end limiting block 33 can restrict the axial movement of the crankshaft 80; after the crankshaft 80 reaches the adjustment position, the tapered positioning shaft 52 can enter the center hole of the crankshaft end through the clearance portion.

[0075] In some embodiments, the clearance portion includes a U-shaped groove opening toward the tapered positioning shaft 52. The width of the U-shaped groove is greater than the outer diameter of the tapered positioning shaft 52 when it enters the central hole, and the bottom of the U-shaped groove is axially opposite to the central hole. The shaft end limiting block 33 is used to abut against the outer peripheral region of the crankshaft end face, and the U-shaped groove is used to avoid the region where the central hole of the crankshaft end is located. Thus, the shaft end limiting block 33 can both restrict the axial movement of the crankshaft 80 and not prevent the tapered positioning shaft 52 from being inserted into the central hole.

[0076] Please see Figure 1 and Figure 5 In this embodiment, the vision inspection module 40 includes an industrial camera and an image processing unit. The industrial camera is used to acquire images of the crankshaft 80. The industrial camera can be positioned above the control station, on one side of the control station, or in conjunction with a light source to acquire images of the crankshaft 80 surface. The image processing unit is coupled to the industrial camera and is used to extract crankshaft features from the crankshaft image and obtain the current loading angle of the crankshaft 80 based on the crankshaft features. The image processing unit can be an industrial computer, a vision controller, an embedded controller, or other processing components with image processing capabilities.

[0077] In some embodiments, the vision inspection module 40 may further include an image acquisition card, a light source, a camera bracket, and a communication unit. The image acquisition card receives image data sent by the industrial camera. The light source provides illumination to the crankshaft 80 at the control station. The camera bracket fixes the industrial camera in the corresponding position. The communication unit enables data transmission between the image processing unit and the control system 60. After the industrial camera acquires an image of the crankshaft, the image processing unit can perform at least one of the following processes on the image: grayscale processing, filtering, edge extraction, contour filtering, arc fitting, feature point extraction, or template matching, to obtain the current loading angle of the crankshaft 80.

[0078] In some embodiments, image acquisition by the visual detection module 40 can be performed step by step.

[0079] The first step is to acquire a low-exposure image to identify reflective areas and the outer contour of the crankshaft.

[0080] The second step is to acquire high-exposure images to identify the connecting rod journal area, crank edge, and end reference.

[0081] The third step involves fusing the available features from the low-exposure image and the high-exposure image to obtain the current loading angle of the crankshaft 80. If the angle difference calculated from the low-exposure image and the high-exposure image exceeds a preset difference value, the image processing unit outputs a signal indicating insufficient recognition confidence.

[0082] In this embodiment, the crankshaft features include main journal features and eccentric portion features. The image processing unit is used to determine the main axis of the crankshaft 80 based on the main journal features, and to obtain the current loading angle based on the orientation relationship of the eccentric portion features relative to the main axis. The main journal features may include the outer contour of the main journal, the center of the main journal, the contours of both ends of the main journal, or an axis obtained by fitting multiple main journal centers. The eccentric portion features include at least one of the connecting rod journal center, the connecting rod journal contour, the crank edge, and the end reference. The image processing unit may first determine the crankshaft main axis, then determine the positional relationship of the eccentric portion features relative to the main axis, and obtain the current loading angle accordingly.

[0083] In some embodiments, the image processing unit may first obtain the main axis line by fitting the contours of two or more main journals, and then obtain the center of the connecting rod journal by fitting the contours of at least one connecting rod journal, using the azimuth angle of the center of the connecting rod journal relative to the main axis line as the current feeding angle.

[0084] In some embodiments, the image processing unit may first perform coarse identification on the crankshaft 80, and then perform fine identification. Coarse identification is used to determine the angle range of the current loading angle of the crankshaft 80. The angle range can be divided according to a preset angle interval. Fine identification is used to further extract the features of the eccentric portion within the angle range determined by coarse identification, and obtain the angle deviation within a smaller range. The control system 60 performs a coarse adjustment action based on the coarse identification result, and performs a fine adjustment action based on the fine identification result.

[0085] In some embodiments, the image processing unit employs a consistency judgment, including:

[0086] A first angle is obtained based on the features of the main journal and the connecting rod journal. A second angle is obtained based on the features of the main journal and the edge of the crank section. A third angle is obtained based on the end reference and the position of the eccentric part. If the difference between at least two of the first, second, and third angles is less than a preset difference, the average value of the corresponding angles is taken as the current feeding angle. If the differences of all three exceed the preset difference, an abnormality signal is output.

[0087] In some embodiments, the crankshaft 80 is a multi-cylinder crankshaft. The image processing unit is also used to acquire the image positions of at least two connecting rod journals and compare the phase relationship between the at least two connecting rod journals with pre-stored phase data. The pre-stored phase data can be stored in the control system 60 or the image processing unit for different crankshaft models. When the phase relationship between at least two connecting rod journals meets the corresponding range, the control system 60 continues to perform subsequent angle adjustment or material handling permission judgment; when the phase relationship between at least two connecting rod journals does not meet the corresponding range, the control system 60 prohibits the output of material handling permission to the upward loading gantry 90.

[0088] Please see Figure 1 , Figure 3 and Figure 5 In this embodiment, the angle adjustment mechanism 50 includes two vertical frames 51, two tapered positioning shafts 52, a feed member 53, and a servo drive 54. The two vertical frames 51 are located on opposite sides of the adjustment station. The two tapered positioning shafts 52 are respectively disposed on the two vertical frames 51 and are used to insert into the center holes at both ends of the crankshaft 80 to clamp the crankshaft 80. The feed member 53 is connected to the tapered positioning shafts 52 and is used to drive the tapered positioning shafts 52 closer to or further away from the ends of the crankshaft 80. The servo drive 54 is drively connected to at least one tapered positioning shaft 52 and is used to drive the tapered positioning shafts 52 and the crankshaft 80 clamped by the tapered positioning shafts 52 to rotate.

[0089] In some embodiments, the feed member 53 can be a cylinder, electric cylinder, lead screw module, guide rail slider mechanism, or other mechanism capable of driving the tapered positioning shaft 52 to move along the crankshaft axis. The servo drive 54 can be a servo motor or a combination of a servo motor and a reducer. The servo drive 54 can be connected to the tapered positioning shaft 52 via a coupling, synchronous belt, gear, rotary connecting plate, or other transmission components. After the two tapered positioning shafts 52 are inserted into the center holes at both ends of the crankshaft 80, the crankshaft 80 can be clamped, and the servo drive 54 can drive the crankshaft 80 to rotate around its own axis.

[0090] In some embodiments, both tapered positioning shafts 52 may be connected to the servo drive 54, or one tapered positioning shaft 52 may be connected to the servo drive 54 while the other tapered positioning shaft 52 rotates driven by the crankshaft 80. The end of the tapered positioning shaft 52 may have a tapered surface to mate with the center hole at the end of the crankshaft. The tapered positioning shaft 52 may also have a replaceable shaft end to adapt to crankshafts 80 with different center hole sizes. The tapered positioning shaft 52 may also be equipped with a positioning detection element to detect whether the tapered positioning shaft 52 is inserted into the center hole at the end of the crankshaft.

[0091] In some embodiments, the angle adjustment mechanism 50 further includes a clamping force detection element. The clamping force detection element can be mounted on the tapered positioning shaft 52, the feed element 53, or the vertical frame 51. The control system 60 determines whether the tapered positioning shaft 52 is properly clamped based on the detection value of the clamping force detection element. When the clamping force is less than a first clamping force threshold, the control system 60 determines that the tapered positioning shaft 52 is not inserted into the center hole or the crankshaft 80 is not properly positioned. When the clamping force is greater than a second clamping force threshold, the control system 60 determines that the clamping force is too large and controls the feed element 53 to retract a preset distance. Only when the clamping force is within the allowable range will the control system 60 allow the servo drive 54 to rotate the crankshaft 80.

[0092] In some embodiments, to reduce the resistance between the crankshaft 80 and the support 32 during rotation, a wear-resistant pad, a rolling support, or a low-friction support may be provided at the V-shaped support opening of the support 32. The wear-resistant pad may be a copper alloy pad, a nylon pad, or other wear-resistant material. The rolling support may be a roller, a needle roller, or a rotatable support. The low-friction support may be located at the contact position between the support 32 and the journal of the crankshaft 80. When the crankshaft 80 rotates under the drive of the tapered positioning shaft 52, the crankshaft 80 is still supported by the support 32, and the rotational resistance is reduced through the aforementioned support structure.

[0093] In some embodiments, an axial clearance may be provided between the shaft end limiting block 33 and the crankshaft end. This axial clearance is used to prevent the shaft end limiting block 33 from axially pressing on the crankshaft 80 when the tapered positioning shaft 52 clamps the crankshaft 80 and drives the crankshaft 80 to rotate. This axial clearance may be less than the allowable axial movement distance of the crankshaft 80 during transport. In this way, the shaft end limiting block 33 can restrict the axial movement of the crankshaft 80 during transport, while reducing the impact on the rotation of the crankshaft 80 during rotation.

[0094] In some embodiments, the rotational action of the servo drive 54 can be performed in stages. The control system 60 determines the coarse adjustment angle and the fine adjustment angle based on the angular deviation. The coarse adjustment angle is less than or equal to the absolute value of the angular deviation, and a buffer angle is reserved before the target loading angle. The servo drive 54 first performs the coarse adjustment action at a first speed, so that the crankshaft 80 enters the vicinity of the target loading angle. The vision inspection module 40 acquires the image of the crankshaft after coarse adjustment and obtains the refined angular deviation. The control system 60 then controls the servo drive 54 to perform the fine adjustment action at a second speed, which is less than the first speed. After the fine adjustment is completed, the vision inspection module 40 acquires the image again for verification.

[0095] In some embodiments, the control system 60 can also compare the actual rotation angle fed back by the servo drive 54 with the angle change amount verified by the image processing unit. If the difference between the actual rotation angle fed back by the servo drive 54 and the angle change amount verified by the image exceeds a preset difference, the control system 60 can determine that there is slippage, insecure clamping, workpiece jamming, or servo execution abnormality, and prohibit the output of material picking permission to the loading gantry 90.

[0096] In this embodiment, the control system 60 may include at least one of a PLC control cabinet, a host computer, a servo controller, and a communication module. The PLC control cabinet can be used to control the start and stop of the feeding mechanism 20, receive sensor signals, and output material handling permission and alarm signals. The host computer or industrial computer can be used to receive the image processing results of the vision inspection module 40 and communicate with the PLC control cabinet. The servo controller can be used to receive the rotation angle, speed, or acceleration / deceleration parameters output by the control system 60 and control the action of the servo drive 54.

[0097] In operation, the control system 60 first controls the feeding mechanism 20 to move, causing the chain 23 to drive the positioning fixture 30 to move along the first direction. When the positioning fixture 30 carrying the crankshaft 80 moves to the adjustment station, the control system 60 controls the feeding mechanism 20 to stop. The vision inspection module 40 acquires an image of the crankshaft 80 located at the adjustment station. The image processing unit determines the crankshaft main axis based on the crankshaft image and identifies at least one eccentric feature. The image processing unit obtains the current feeding angle based on the orientation relationship of the eccentric feature relative to the main axis. The control system 60 obtains the angle deviation based on the current feeding angle and the target feeding angle. When the angle deviation exceeds the preset allowable range, the control system 60 controls the angle adjustment mechanism 50 to operate.

[0098] When the angle adjustment mechanism 50 is activated, the two feed members 53 respectively drive the two tapered positioning shafts 52 to move towards both ends of the crankshaft 80, so that the two tapered positioning shafts 52 are respectively inserted into the center holes at both ends of the crankshaft 80. Since the shaft end limiting block 33 has a clearance part opposite to the center hole, the tapered positioning shaft 52 can avoid the shaft end limiting block 33 when entering the center hole. After the two tapered positioning shafts 52 clamp the crankshaft 80, the servo drive member 54 drives at least one tapered positioning shaft 52 to rotate according to the angle deviation, thereby driving the crankshaft 80 to rotate around its own axis under the support of the positioning fixture 30.

[0099] In some embodiments, after the angle adjustment mechanism 50 drives the crankshaft 80 to rotate, the control system 60 controls the vision detection module 40 to acquire the crankshaft image again. The image processing unit obtains the verification feeding angle based on the re-acquired image, and the control system 60 obtains the verification deviation based on the verification feeding angle and the target feeding angle. When the verification deviation is within a preset allowable range, the control system 60 outputs a material handling permission to the feeding gantry 90. When the verification deviation exceeds the preset allowable range, the control system 60 continues to control the angle adjustment mechanism 50 to drive the crankshaft 80 to rotate, or outputs an abnormal signal and prohibits the output of a material handling permission to the feeding gantry 90. Thus, the feeding gantry 90 only removes the crankshaft 80 after the crankshaft 80 angle reaches the corresponding condition.

[0100] In some embodiments, the control system 60 can also control the rotation speed of the angle adjustment mechanism 50 according to the magnitude of the angle deviation. When the angle deviation is greater than a first threshold, the control system 60 controls the angle adjustment mechanism 50 to drive the crankshaft 80 to rotate at a first speed. When the angle deviation is less than or equal to the first threshold and greater than a second threshold, the control system 60 controls the angle adjustment mechanism 50 to drive the crankshaft 80 to rotate at a second speed, which is less than the first speed. The first and second thresholds can be determined based on the crankshaft model, crankshaft weight, crankshaft eccentricity distribution, servo drive parameters, or loading cycle time. The first and second speeds can also correspond to different acceleration or deceleration parameters.

[0101] In some embodiments, the control system 60 may also set a third threshold. When the angular deviation is less than or equal to a second threshold and greater than a third threshold, the control system 60 controls the servo drive 54 to rotate in a jogging manner. The jogging manner may include single-pulse rotation, short-distance rotation, or low-speed short-time rotation. After each jog, the vision detection module 40 acquires the crankshaft image again and updates the angular deviation. When the angular deviation is less than or equal to the third threshold, the control system 60 outputs a verification command. Thus, the crankshaft 80 rotation action may include three stages: coarse adjustment, fine adjustment, and jogging confirmation.

[0102] In some embodiments, the visual inspection module 40 is also used to output a recognition confidence score. The recognition confidence score can be obtained based on the integrity of crankshaft features, template matching results, edge fitting results, or phase comparison results. When the recognition confidence score is lower than a preset value, the control system 60 controls the angle adjustment mechanism 50 to rotate the crankshaft 80 by a predetermined trial angle, and controls the visual inspection module 40 to acquire the crankshaft image again. The predetermined trial angle can be determined based on the crankshaft model or based on the feature occlusion area in the previous frame image. By acquiring the image again, the influence of partial occlusion, surface reflection, or oil stains on the recognition results can be reduced.

[0103] In some embodiments, when the recognition confidence level is lower than a preset value, the control system 60 first controls the light source to change the illumination parameters and re-acquire the image. If the recognition confidence level after the re-acquisition is still lower than the preset value, the angle adjustment mechanism 50 is then controlled to drive the crankshaft 80 to rotate a predetermined trial angle. The illumination parameters may include the light source brightness, exposure time, light source on-state area, or shooting angle. When the recognition confidence level after the trial rotation is still lower than the preset value, the control system 60 outputs a recognition anomaly signal and prohibits the output of material handling permission to the upward material gantry 90.

[0104] In some embodiments, the control system 60 stores identification templates, target loading angles, allowable angle errors, and servo control parameters corresponding to multiple crankshaft models. The identification templates may include main journal feature templates, connecting rod journal feature templates, end reference templates, or multi-link journal phase data. The target loading angle can be the angle that the crankshaft 80 needs to reach when it is taken away by the loading truss 90. The allowable angle error can be the permissible deviation of the current loading angle relative to the target loading angle. The servo control parameters may include at least one of rotational speed, acceleration, deceleration, stop holding time, and number of checks.

[0105] In some embodiments, the current crankshaft model can be obtained from a model acquisition component or automatically identified by the vision inspection module 40 based on crankshaft end features, crankshaft length, number of connecting rod journals, or phase relationship. The control system 60 can compare the crankshaft model obtained from the model acquisition component with the crankshaft model identified by the vision inspection module 40. If they match, the control system 60 calls the corresponding parameters. If they do not match, the control system 60 prohibits the output of material handling permission and prompts for verification of the crankshaft model or positioning fixture 30.

[0106] In some embodiments, the crankshaft loading angle control system further includes a model acquisition component. The model acquisition component is coupled to the control system 60 and is used to acquire the current crankshaft model. The model acquisition component may include at least one of a barcode scanner, a tooling identification sensor, a manual input unit, and a host computer communication unit. The barcode scanner can read the identification code on the crankshaft 80 or the material frame. The tooling identification sensor can identify the identification component on the positioning tooling 30. The manual input unit can be a touch screen or a button panel. The host computer communication unit can receive model information sent by the production line master control system. After acquiring the current crankshaft model, the control system 60 calls the corresponding identification template, target loading angle, allowable angle error, and servo control parameters.

[0107] In some embodiments, the system may further include a sensor assembly 70. The sensor assembly 70 includes a first sensor 71 and a second sensor 72. The first sensor 71 is located at the blank loading position and is used to detect whether the crankshaft 80 is present at the blank loading position. The second sensor 72 is located at the control station or the material handling station and is used to detect whether the crankshaft 80 is present at the control station or the material handling station. The control system 60 controls the loading mechanism 20 to stop based on the arrival signal of the second sensor 72. When neither the first sensor 71 nor the second sensor 72 detects the crankshaft 80, the control system 60 outputs a no-material alarm signal.

[0108] In some embodiments, the control system 60 has an automatic mode and a manual mode. In automatic mode, the control system 60 operates in the sequence of arrival detection, image acquisition, angle adjustment, verification, and material handling authorization. In manual mode, the control system 60 responds to a manual trigger signal, causing the feeding mechanism 20 to move one station at a time. The manual mode can be used for manual material replenishment, model changeover, debugging, or maintenance. When the hopper is full or debugging is completed, the control system 60 can switch to automatic mode, allowing the system to be connected to the production line for continuous operation.

[0109] In some embodiments, the automatic mode may further include a pre-station detection step. The crankshaft 80 passes through a pre-station before entering the control station. A pre-detection element is provided at the pre-station. The pre-detection element can detect whether the crankshaft 80 is placed on the positioning fixture 30 and whether the crankshaft 80 has experienced axial displacement. If the pre-station detection does not meet the conditions, the loading mechanism 20 stops, and the control system 60 outputs an abnormal signal. If the pre-station detection meets the conditions, the loading mechanism 20 continues to transport the crankshaft 80 to the control station.

[0110] Please see Figure 6 This embodiment also provides a crankshaft loading angle control method. This method can be executed by the aforementioned crankshaft loading angle control system, or by other equipment capable of performing the same action. The method may include the following steps.

[0111] S101, the feeding mechanism 20 conveys the crankshaft 80 located on the positioning fixture 30. The control system 60 controls the drive component 21 to move, and the drive component 21 drives the chain 23 to move through the drive sprocket 22. The chain 23 drives the positioning fixture 30 and the crankshaft 80 to move along the first direction. When the crankshaft 80 moves to a preset distance in front of the adjustment station, the control system 60 can control the feeding mechanism 20 to switch from the first conveying speed to the second conveying speed; when the second sensor 72 detects that the crankshaft 80 has arrived at the position, the control system 60 controls the feeding mechanism 20 to stop.

[0112] S102, the visual inspection module 40 acquires an image of the crankshaft 80. The visual inspection module 40 can first acquire a low-exposure image, then acquire a high-exposure image, and fuse the usable features in the low-exposure and high-exposure images. The visual inspection module 40 can also perform initial sampling before the crankshaft 80 is clamped by the angle adjustment mechanism 50, and perform confirmation sampling after the crankshaft 80 is clamped by the tapered positioning shaft 52.

[0113] S103, determine the main axis of crankshaft 80 based on the image of crankshaft 80. The image processing unit can first extract the main journal profile of crankshaft 80, then fit the main journal center based on the main journal profile, and then determine the main axis based on at least two main journal centers. When only one main journal feature is available, the image processing unit can also determine the main axis by combining the positional relationship of the end reference or positioning fixture 30.

[0114] S104, determine at least one off-center feature based on the image of crankshaft 80. The off-center feature may include at least one of connecting rod journal center, connecting rod journal profile, crank edge, and end reference. The image processing unit may determine the off-center feature through edge extraction, contour fitting, template matching, or feature point matching.

[0115] S105, based on the orientation relationship of the eccentric part characteristics relative to the main axis, the current loading angle of crankshaft 80 is obtained. The current loading angle can be obtained by the azimuth angle of the connecting rod journal center relative to the main axis, or by the angle between the crank edge or end reference and the main axis.

[0116] S106: The angle deviation is obtained based on the current feeding angle and the target feeding angle. The target feeding angle can be called by the control system 60 according to the current crankshaft model, or it can be issued by the host computer. The control system 60 compares the current feeding angle with the target feeding angle to obtain the angle deviation.

[0117] S107, based on the angular deviation, the angle adjustment mechanism 50 drives the crankshaft 80 to rotate around its own axis. Specifically, the two feed members 53 respectively drive the two tapered positioning shafts 52 to move towards both ends of the crankshaft 80, so that the two tapered positioning shafts 52 are respectively inserted into the center holes at both ends of the crankshaft 80. The clamping force detection member detects the clamping state of the tapered positioning shafts 52. When the clamping force is within the allowable range, the control system 60 controls the servo drive member 54 to drive at least one tapered positioning shaft 52 to rotate, thereby driving the crankshaft 80 to rotate around its own axis under the support of the positioning fixture 30.

[0118] In S107, the crankshaft 80 can be controlled to rotate in segments based on the magnitude of the angular deviation. When the angular deviation is greater than a first threshold, the angle adjustment mechanism 50 is controlled to rotate the crankshaft 80 at a first speed; when the angular deviation is less than or equal to the first threshold and greater than a second threshold, the angle adjustment mechanism 50 is controlled to rotate the crankshaft 80 at a second speed, which is less than the first speed; when the angular deviation is less than or equal to the second threshold and greater than a third threshold, the angle adjustment mechanism 50 is controlled to rotate the crankshaft 80 in a jogging manner. After each jogging, the vision detection module 40 acquires the crankshaft image again and updates the angular deviation.

[0119] In step S108, after the angle adjustment mechanism 50 rotates the crankshaft 80, the vision detection module 40 acquires an image of the crankshaft 80 again. This re-acquisition of the image can use the same sampling method as in step S102, or it can use a single sampling method. If the surface of the crankshaft 80 is reflective or has partial obstruction, the brightness of the light source or the exposure time can be adjusted before acquiring the image again.

[0120] S109, the verification feeding angle is obtained based on the re-acquired image, and the verification deviation is obtained based on the verification feeding angle and the target feeding angle. The image processing unit can redetermine the main axis and eccentricity features, and recalculate the verification feeding angle. The control system 60 calculates the verification deviation based on the verification feeding angle and the target feeding angle.

[0121] S110, determine whether the verification deviation is within the preset allowable range. When the verification deviation is within the preset allowable range, the control system 60 outputs a material handling permission to the upward truss 90. When the verification deviation is not within the preset allowable range, the control system 60 may continue to control the angle adjustment mechanism 50 to drive the crankshaft 80 to rotate, or it may output an abnormal signal and prohibit the output of a material handling permission to the upward truss 90.

[0122] In some embodiments, obtaining the current loading angle from the crankshaft image may include a coarse recognition step and a fine recognition step. In the coarse recognition step, the image processing unit determines the angle range in which the current loading angle of the crankshaft 80 lies based on the crankshaft outer contour, end reference, or connecting rod journal region. In the fine recognition step, the image processing unit extracts the main journal features and eccentric part features within this angle range, and calculates the orientation relationship of the eccentric part features relative to the main axis to obtain the current loading angle. If the results obtained from the coarse recognition step and the fine recognition step are inconsistent, the image processing unit outputs a recognition confidence insufficient signal.

[0123] In some embodiments, the clamping of the crankshaft 80 by the tapered positioning shafts 52 may include a proximity step, an insertion step, a clamping force judgment step, and a clamping confirmation step. In the proximity step, the two tapered positioning shafts 52 move toward both ends of the crankshaft 80. In the insertion step, the two tapered positioning shafts 52 respectively enter the center holes at both ends of the crankshaft 80. In the clamping force judgment step, the axial force on the tapered positioning shafts 52 or the load on the feed member 53 is detected. In the clamping confirmation step, when the clamping force is within the allowable range, clamping is confirmed to be complete; when the clamping force is not within the allowable range, the servo drive member 54 is prohibited from performing rotational actions.

[0124] In some embodiments, when the recognition confidence level is lower than a preset value, the light source brightness or exposure time can be changed before acquiring the image again. If the recognition confidence level is still lower than the preset value after re-acquisition, the crankshaft 80 is controlled to rotate a predetermined trial angle and the image is acquired again. If the recognition confidence level is still lower than the preset value after the trial rotation, an recognition anomaly signal is output, and the output of material handling permission to the upward truss 90 is prohibited.

[0125] In some embodiments, servo feedback can also be compared with visual verification. The control system 60 acquires the actual rotation angle fed back by the servo drive 54 and acquires the change in image angle calculated by the visual detection module 40 before and after rotation. When the difference between the actual rotation angle and the change in image angle is less than a preset difference, the verification judgment continues. When the difference between the actual rotation angle and the change in image angle is greater than or equal to the preset difference, a clamping abnormality or execution abnormality signal is output.

[0126] In some embodiments, a material handling permit confirmation step can also be performed before issuing the material handling permit. The material handling permit confirmation step includes confirming that the verification deviation is within a preset allowable range, confirming that the tapered positioning shaft 52 has retracted to the material handling clearance position, and confirming that the loading gantry 90 is in a material handling state. After all the above conditions are met, the control system 60 issues a material handling permit to the loading gantry 90. If any condition is not met, the control system 60 does not issue a material handling permit.

[0127] In some embodiments, a reset step can also be performed after the loading gantry 90 removes the crankshaft 80. The reset step includes controlling the tapered positioning shaft 52 to retract from the center hole at the end of the crankshaft, controlling the loading mechanism 20 to move one station, and controlling the vision detection module 40 to wait for the next crankshaft image acquisition. If the control station sensor still detects the crankshaft 80 after the loading gantry 90 removes it, the control system 60 outputs a material handling abnormality signal. If the control station sensor does not detect the crankshaft 80, the loading mechanism 20 is allowed to move to the next station.

[0128] Using the aforementioned system and method, after the feeding mechanism 20 delivers the crankshaft 80 to the control station, the vision inspection module 40 obtains the current feeding angle of the crankshaft 80. The control system 60 calculates the angle deviation based on the current feeding angle and the target feeding angle, and controls the angle control mechanism 50 to rotate the crankshaft 80. After the crankshaft 80 rotates, it is rechecked by the vision inspection module 40. If the rechecked deviation is within the preset allowable range, the control system 60 outputs a material removal permit to the feeding gantry 90. Furthermore, in different embodiments, the system can be adapted to different crankshaft specifications and different field conditions by using crankshaft model parameter calls, multi-feature consistency judgment, multi-link journal phase comparison, clamping force judgment, staged rotation, identification confidence resampling, servo feedback comparison, and multi-condition judgment of material removal permits.

[0129] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and concept of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A crankshaft loading angle control system, used to adjust the crankshaft loading angle before the loading truss removes the crankshaft, comprising: frame; A feeding mechanism, located on the frame, is used to convey the crankshaft along a first direction; A positioning fixture is provided on the feeding mechanism to support the crankshaft; A vision inspection module is used to acquire an image of the crankshaft located at the control station and to obtain the current loading angle of the crankshaft based on the image. Angle adjustment mechanism, used to drive the crankshaft to rotate around its own axis; and The control system, coupled to the feeding mechanism, the vision detection module, and the angle adjustment mechanism, is used for: The feeding mechanism is controlled to move the positioning fixture carrying the crankshaft to the control station; The vision detection module is controlled to acquire an image of the crankshaft located at the control station, and the current loading angle of the crankshaft is obtained based on the image; The angle deviation is obtained based on the current feeding angle and the target feeding angle. The angle adjustment mechanism is controlled according to the angle deviation to drive the crankshaft to rotate, so that the current feeding angle of the crankshaft is close to or reaches the target feeding angle; When the current loading angle of the crankshaft meets the preset allowable range, a material handling permission is output to the loading truss.

2. The crankshaft feeding angle control system according to claim 1, wherein the feeding mechanism comprises: The drive unit is located on the frame; The drive sprocket is connected to the drive component for transmission. The driven sprocket is spaced apart from the driving sprocket; and A chain is wound around the driving sprocket and the driven sprocket; The positioning fixtures are multiple, and the multiple positioning fixtures are spaced apart on the chain along the first direction. The driving member is used to drive the chain to move through the drive sprocket, so that the multiple positioning fixtures move sequentially along the first direction. The positioning fixture includes a positioning base plate, two support seats and a shaft end limiting block. The positioning base plate is connected to the chain. The two support seats are disposed on the positioning base plate and are used to support the journals of the crankshaft respectively. The shaft end limiting block is disposed on the positioning base plate and is used to restrict the crankshaft from moving axially.

3. The crankshaft feeding angle control system according to claim 2, wherein the support base is provided with a V-shaped support opening for supporting the crankshaft; The positioning base plate is provided with multiple sets of mounting holes arranged at intervals along the first direction. The two support seats are connected to the positioning base plate through different sets of mounting holes to adjust the distance between the two support seats.

4. The crankshaft loading angle control system according to claim 1, wherein the vision inspection module comprises: An industrial camera is used to acquire images of the crankshaft; and An image processing unit, coupled to the industrial camera, is used to extract crankshaft features from the image of the crankshaft and obtain the current loading angle of the crankshaft based on the crankshaft features; The crankshaft features include main journal features and eccentric part features. The image processing unit is used to determine the main axis of the crankshaft based on the main journal features and to obtain the current loading angle based on the orientation relationship of the eccentric part features relative to the main axis. The eccentric features include at least one of the following: connecting rod journal center, connecting rod journal profile, crank edge, and end reference.

5. The crankshaft feeding angle control system according to claim 4, wherein the crankshaft is a multi-cylinder crankshaft, and the image processing unit is further configured to acquire the image positions of at least two connecting rod journals and compare the phase relationship between the at least two connecting rod journals with pre-stored phase data; The control system is also used to prohibit the output of material handling permission to the loading truss when the phase relationship does not meet the range corresponding to the pre-stored phase data.

6. The crankshaft feeding angle control system according to claim 2, wherein the angle adjustment mechanism comprises: Two vertical frames are located on either side of the control station; Two tapered positioning shafts are respectively disposed on the two vertical frames and are used to be inserted into the center holes at both ends of the crankshaft to clamp the crankshaft; the shaft end limiting block is provided with a clearance part, which is disposed opposite to the center hole at the end of the crankshaft to avoid the tapered positioning shaft when it is inserted into the center hole; A feed element, connected to the tapered positioning shaft, is used to move the tapered positioning shaft closer to or away from the end of the crankshaft; and A servo drive is connected to at least one of the tapered positioning shafts for driving the tapered positioning shafts and the crankshaft held by the tapered positioning shafts to rotate.

7. The crankshaft feeding angle control system according to claim 1, wherein the control system is further used for: After the angle adjustment mechanism drives the crankshaft to rotate, the vision detection module is controlled to acquire an image of the crankshaft again. The loading angle is verified based on the re-acquired image; The verification deviation is obtained based on the verification feeding angle and the target feeding angle. When the verification deviation is within the preset allowable range, the material picking permission is output to the loading gantry; When the verification deviation exceeds the preset allowable range, the angle adjustment mechanism continues to drive the crankshaft to rotate, or an abnormal signal is output and the material picking permission is prohibited from being output to the loading gantry.

8. The crankshaft feeding angle control system according to claim 1, wherein the control system is further used for: When the angle deviation is greater than a first threshold, the angle adjustment mechanism is controlled to drive the crankshaft to rotate at a first speed; when the angle deviation is less than or equal to the first threshold and greater than a second threshold, controlling the angle regulation mechanism to rotate the crankshaft at a second speed, wherein The second speed is less than the first speed; The visual detection module is also used to output the recognition confidence level. The control system is also used to control the angle adjustment mechanism to drive the crankshaft to rotate a predetermined trial angle when the recognition confidence level is lower than a preset value, and to control the visual detection module to acquire the image of the crankshaft again.

9. The crankshaft loading angle control system according to claim 1, wherein the control system stores multiple identification templates corresponding to crankshaft models, target loading angles, allowable angle errors, and servo control parameters; The control system is also used to call the corresponding identification template, the target loading angle, the allowable angle error, and the servo control parameters according to the current crankshaft model; The crankshaft loading angle control system further includes a model acquisition component, which is coupled to the control system and is used to acquire the current crankshaft model. The model acquisition component includes at least one of a barcode scanner, a tooling identification sensor, a manual input unit, and a host computer communication unit.

10. A crankshaft loading angle control method, used to adjust the crankshaft loading angle before the loading truss removes the crankshaft, comprising: The feeding mechanism conveys the crankshaft positioned on the positioning fixture; After the feeding mechanism delivers the crankshaft to the control station, the vision inspection module acquires an image of the crankshaft. Determine the main axis of the crankshaft based on the image of the crankshaft; Based on the image of the crankshaft, at least one eccentric feature is determined, the eccentric feature including at least one of the following: connecting rod journal center, connecting rod journal profile, crank edge, and end reference; Based on the orientation relationship between the eccentric part and the main axis, the current loading angle of the crankshaft is obtained; The angle deviation is obtained based on the current feeding angle and the target feeding angle. Based on the angle deviation, the angle adjustment mechanism drives the crankshaft to rotate around its own axis so that the current feeding angle of the crankshaft approaches or reaches the target feeding angle. After the angle adjustment mechanism drives the crankshaft to rotate, the vision detection module acquires an image of the crankshaft again. The verification feeding angle is obtained from the re-acquired image, and the verification deviation is obtained from the verification feeding angle and the target feeding angle. When the verification deviation is within the preset allowable range, a material handling permit is issued to the loading truss.

Images