SUMMERY OF THE UTILITY MODEL
To current technical problem, the utility model aims to provide a extracting device based on vision is followed, it has the extension robot and can snatch when the object long, reduces to wait to snatch the advantage that the object was omitted.
In order to achieve the above purpose, the utility model provides a following technical scheme: the invention provides the following technical scheme: a material extracting device based on vision following comprises:
the top surface of the workbench is a horizontal table surface;
the conveying belt is arranged on the table top and used for conveying objects;
a vision system mounted on the table, having a shooting view directly facing a position near the front side in the conveying direction of the conveyor belt, and outputting position information of the object based on the shot image;
the industrial robot is arranged on the workbench, is arranged close to the position at the rear side in the conveying direction of the conveying belt, has a working range for grabbing the position at the rear side in the conveying direction of the conveying belt, and has a working range staggered with the visual field of the visual system;
the output shaft of the encoder is in transmission connection with the conveyor belt and is used for outputting a position signal of the conveyor belt;
the robot master control is used for electrically connecting the vision system, the encoder and the industrial robot and controlling the industrial robot to execute the grabbing action based on signals output by the encoder and the vision system.
By adopting the technical scheme, the visual system and the industrial robot are respectively arranged on the front side and the rear side of the conveyor belt, so that the working range of the industrial robot and the visual field of the visual system are staggered, and in addition, the conveyor belt is connected with an encoder; when the vision system detects an object, the robot can acquire the real-time position of the object by the main control of the object position of the vision system and the position of the conveyor belt output by the encoder; therefore, after the object enters the working range of the industrial robot, the industrial robot can execute grabbing, the range of the industrial robot capable of grabbing the object is enlarged, the length of the robot capable of grabbing the object is prolonged, and the robot is beneficial to the fact that the industrial robot grabs the object on the conveying belt.
The utility model discloses further set up to: the conveying belt comprises a conveying main body and a conveying belt body sleeved on the conveying main body; the front side of the transmission main body is provided with a light increasing source for improving the shooting visual field brightness of the visual system.
By adopting the technical scheme, the light increasing source is arranged on the front side of the transmission main body, so that the shooting visual field brightness of the visual system is improved, and the recognition rate of the visual system to objects is improved.
The utility model discloses further set up to: the light enhancement source comprises light supplement lamp strips horizontally arranged in the conveying direction of the two eye conveying belts, and the two light supplement lamp strips are oppositely arranged on two sides of the conveying belt located in the visual field of the visual system and the light emitting surfaces of the two light supplement lamp strips are right opposite.
By adopting the technical scheme, the light supplementing lamp strips are arranged along the conveying direction of the conveying belt and can emit uniform light intensity to the area in the conveying direction of the conveying belt, and the light intensity of the light supplementing lamp strips on the two sides is complementary to that of the light irradiating lamp strips, so that the light intensity of the conveying belt vertical to the conveying direction is uniform; therefore, the whole light supplement of the shooting visual field of the visual system can be uniform by combining the two.
The utility model discloses further set up to: all be provided with L type frame between the both ends of light filling lamp strip and the lateral wall of conveying main part, L type frame includes that one end is fixed the horizontal hack lever in the conveying main part and is connected perpendicularly in the vertical hack lever of the horizontal hack lever other end, but vertical hack lever level slides on horizontal hack lever, but light filling lamp strip vertical slide on vertical hack lever.
By adopting the technical scheme, the vertical frame rod can horizontally slide on the horizontal frame rod, and the light supplementing lamp bar can vertically slide on the vertical frame rod; the position of the light supplementing lamp strip can be adjusted to a proper position on a plane perpendicular to the conveying direction of the conveying belt according to requirements and is not completely fixed.
The utility model discloses further set up to: one side of the encoder is fixed on the outer side wall of the conveying main body, an output shaft is arranged on the other side of the encoder, a synchronizing wheel is fixedly connected to the output shaft of the encoder, and the synchronizing wheel is in butt joint with the conveying belt in a transmission mode.
Through adopting above-mentioned technical scheme, through synchronizing wheel linkage encoder and conveyer belt, can acquire the positional information of conveyer belt on ordinary motor drive's conveyer belt, but the assembling nature is stronger.
The utility model discloses further set up to: the industrial robot comprises an industrial robot body and an end effector arranged on an output shaft of the industrial robot body, wherein the industrial robot body adopts a SCARA robot.
Through adopting above-mentioned technical scheme, SCARA robot is four-axis robot, compares in the number of axles that six industrial robot needs control few.
The utility model discloses further set up to: a fixing plate extending out along the radial direction is horizontally fixed on an output shaft of the industrial robot body, one end of the fixing plate is fixed on the output shaft of the industrial robot body, and the end effector is fixed at the other end of the fixing plate.
Through adopting above-mentioned technical scheme, connect end effector through the fixed plate for produce the interval between end effector and the output shaft, be favorable to end effector wiring, also make end effector simultaneously and can be circular motion around the output shaft.
The utility model discloses further set up to: the end effector adopts a suction nozzle, the suction nozzle vertically penetrates and is fixed on the fixing plate, and the upper end of the suction nozzle is connected with an air pipe and is connected with an electromagnetic valve and an external air supply source through the air pipe.
Through adopting above-mentioned technical scheme, use the suction nozzle to adsorb and compare in the manipulator of centre gripping class, the applied condition is more stable.
The utility model discloses further set up to: install the shading safety cover on the mesa of workstation, the shading safety cover includes the cover body and four spinal branch vaulting poles of fixing on four corners of cover body bottom, and four spinal branch vaulting poles are fixed connection respectively on four corners of mesa, and four spinal branch vaulting poles are with the cover body set up high for there is the interval between the bottom surface of the transport plane of the conveyer belt body and the cover body.
Through adopting above-mentioned technical scheme, the shading safety cover can enough play the shading and can also play the effect of protection, guarantees that the illumination condition is stable under the environment at vision system place, and whole device is difficult for receiving outside intrusion.
The utility model discloses further set up to: the cover body is provided with four shielding surfaces and an opening, the four shielding surfaces are respectively positioned at the top and three side parts, and one surface of the opening is arranged in the conveying direction parallel to the conveying belt.
By adopting the technical scheme, the opening is formed in the cover body, so that both light blocking protection and debugging operation are considered.
Compared with the prior art, the beneficial effects of the utility model are that:
(1) the working range of the industrial robot is staggered with the visual field of the visual system, and the industrial robot is controlled to adopt a following grabbing method, so that the object grabbing range of the industrial robot is enlarged, and the industrial robot is facilitated to grab objects on the conveyor belt;
(2) by arranging the light supplementing lamp bar and the light shield, the vision system can be in a relatively stable illumination environment, and the object identification by the vision system is facilitated;
(3) through setting up through synchronizing wheel linkage encoder and conveyer belt, can acquire the positional information of conveyer belt on ordinary motor drive's conveyer belt, but the assembling nature is stronger.
In an embodiment, a material taking device based on visual following is shown in fig. 1 and comprises a workbench 1, a visual system 6, an industrial robot 2, a conveyor belt 3, an encoder 4 and a robot main control 5. The top surface of the workbench 1 is a horizontal table surface; the conveyor belt 3 is horizontally arranged on the table top and used for conveying objects; the vision system 6 is arranged on the worktable 1 and the shooting visual field thereof is over against the position near the front side in the conveying direction of the conveyor belt 3; the industrial robot 2 is installed on the worktable 1 and is arranged near the position near the rear side in the conveying direction of the conveyor belt 3, and has a working range for performing grabbing on the position near the rear side in the conveying direction of the conveyor belt 3, and the working range of the industrial robot 2 and the visual field of the vision system 6 are staggered. An output shaft of the encoder 4 is in transmission connection with the conveyor belt 3, and the encoder 4 acquires the transmission position of the conveyor belt 3 and is used for outputting a position signal indicating the position of the conveyor belt 3. The robot master control 5 is electrically connected with the vision system 6, the encoder 4 and the industrial robot 2, and controls the industrial robot 2 to execute the grabbing action based on signals output by the encoder 4 and the vision system 6.
The robot master 5 reads the position signal output by the encoder 4 in real time to acquire the position of the conveyor belt 3. After the conveyor belt 3 moves for a fixed length, the robot main control 5 outputs a signal to the vision system 6, the vision system 6 starts to photograph and recognize after receiving the signal, and meanwhile, the robot main control 5 records the current position of the conveyor belt 3 as the reference position of the object recognized by the current vision system 6.
When the robot main control 5 judges that the object moves into the working range of the industrial robot 2, the robot main control 5 starts to control the industrial robot 2 to execute the following grabbing action. If multiple objects are identified by the vision system 6, then multiple data will be sent to the robot master 5. When the robot main control 5 controls the industrial robot 2 to complete the grabbing, if an object exists in the working range of the industrial robot 2, the robot main control 5 continues to control the industrial robot 2 to execute the grabbing action.
As shown in fig. 1 and 2, the upper table surface of the working table 1 is rectangular, and the conveyor belt 3 is horizontally arranged in the middle of the table surface of the working table 1 in the width direction. And both ends of the conveyor belt 3 are respectively extended from both sides in the length direction of the table surface. The conveyor belt 3 comprises a conveying body 7 and a conveyor belt body 8 sleeved on the conveying body 7.
As shown in fig. 1 and 2, a light-shielding protective cover 9 is mounted on the table top of the table 1, and the light-shielding protective cover 9 is completely covered on the table top. The shading protective cover 9 comprises a cover body 10 and four supporting rods 11 fixed on four corners of the bottom of the cover body 10, wherein the four supporting rods 11 are respectively fixedly connected on the four corners of the table top to fix the cover body 10 and the table top. In addition, the four support rods 11 elevate the cover 10, so that a certain distance exists between the conveying plane of the conveyor belt body 8 and the bottom surface of the cover 10, and the cover 10 does not influence the conveyor belt 3 to convey objects.
As shown in fig. 1 and 2, the cover 10 has four shielding surfaces and one opening, the four shielding surfaces are respectively located at the top and three sides, and one side of the opening is arranged in parallel to the conveying direction of the conveyor belt 3. The provision of four shielding surfaces and one opening allows the mask body 10 to provide both light blocking protection and commissioning.
As shown in fig. 1 and 2, the vision system 6 includes a camera 12 and an image calculator 13. The camera 12 is fixed on the top shielding surface of the cover 10 right above the conveyor belt 3, and the lens of the camera 12 faces the conveyor belt 3 to acquire the area of the conveyor belt 3 at the front side of the table top as a shooting view. The image calculator 13 is installed on the side wall of the opening of the cover 10 on the workbench 1, and the image calculator 13 acquires image data taken by the camera 12, can calculate the object position through contour analysis, and outputs the object position to the robot main control 5.
Further, as shown in fig. 1 and 2, a light increasing source 14 for increasing the brightness of the visual field of the vision system 6 is arranged on the front side of the transmission body 7. The light-adding source 14 comprises two horizontally arranged light-supplementing light bars 15, the two light-supplementing light bars 15 are oppositely arranged on two sides of the conveyor belt 3 below the camera 12, and light-emitting surfaces of the light-supplementing light bars are opposite; two light filling lamp strips 15 are a little higher than the height on 3 planes of conveyer belt. Under the light filling effect of two light filling lamp strips 15, can promote the regional luminance of 3 of conveyer belts that camera 12 shot to the article of image calculator 13 discernment shooting on conveyer belt 3.
Specifically, as shown in fig. 1 and 2, L-shaped frames 16 are disposed between two ends of the light supplementing light bar 15 and the outer side wall of the transmission main body 7, and each L-shaped frame 16 includes a horizontal frame bar with one end fixed on the transmission main body 7 and a vertical frame bar vertically connected to the other end of the horizontal frame bar. The vertical frame rod can horizontally slide on the horizontal frame rod, and the light supplementing light bar 15 can vertically slide on the vertical frame rod; the mode that slides can set up the slide opening of rectangular shape at the length directionality of vertical hack lever and horizontal hack lever, and between horizontal hack lever and the vertical hack lever and all adopt the screw to support tight mode between vertical hack lever and light filling lamp strip 15 and fix for vertical hack lever can be fixed in the length direction of horizontal hack lever in the rectangular downthehole arbitrary department of rectangular, light filling lamp strip 15 also can be fixed in the rectangular downthehole arbitrary department of vertical hack lever.
As shown in fig. 1 and 2, the industrial robot 2 is mounted on the side of the table surface remote from the opening of the enclosure 10, on the inner side of the conveyor belt 3. The industrial robot 2 comprises a robot body 17 and an end effector 18. The robot body 17 is a four-axis horizontal articulated SCARA robot. Therefore, the output shaft of the robot body 17 can perform translation of the X-axis and the Y-axis, lifting of the Z-axis and rotation of the a-axis under the control of the robot main control 5.
As shown in fig. 1 and 2, the end effector 18 is mounted on an output shaft of the robot body 17, specifically, a fixing plate 19 extending in the radial direction is horizontally fixed on the output shaft of the robot body 17, and the end effector 18 is fixed on one end of the fixing plate 19 away from the output shaft of the robot body 17. Therefore, when the output shaft of the robot body 17 rotates along the a axis, the end effector 18 performs a circular motion around the axis of the output shaft of the robot body 17, the radius of the circular motion being substantially equal to the length between the two ends of the fixed plate 19.
As shown in fig. 1 and 2, the end effector 18 is a suction nozzle vertically fixed on the fixing plate 19, the upper end of the suction nozzle is connected with an air pipe 20 and connected with an electromagnetic valve (not shown in the figures) and an external air pump through the air pipe 20, and the robot main control 5 is electrically connected with the electromagnetic valve and can control the on-off of the electromagnetic valve. The air pump provides the power supply of suction for the air supply, switches on the suction nozzle and can produce the suction of adsorbed object when the solenoid valve, and can lose the suction of adsorbed object when the solenoid valve disconnection suction nozzle. Therefore, when the robot needs to grab an object, the robot main control 5 conducts the electromagnetic valve; when the object needs to be put down, the robot main control unit 5 closes the electromagnetic valve.
As shown in fig. 1 and 2, one side of the encoder 4 is fixed on the outer side wall of the transmission main body 7, the other end of the encoder 4 is provided with an output shaft, a synchronizing wheel 22 is fixedly connected to the output shaft of the encoder 4, and the synchronizing wheel 22 abuts against the conveyor belt body 8, so that when the conveyor belt 3 moves, the synchronizing wheel 22 can be driven to rotate, and the encoder 4 can convert the displacement of the conveyor belt 3 into a position signal of the encoder 4.
A material taking method using a material taking device based on visual following, as shown in figure 3,
s10, initializing a robot main control 5, and starting the industrial robot 2, the conveyor belt 3, the encoder 4 and the vision system 6;
referring to fig. 4, the robot master 5 initialization process includes:
s11, establishing a workbench 1 coordinate system shared by the industrial robot 2 and the vision system 6;
as shown in fig. 5, the robot master 5 calibrates a table 1 coordinate system. Three non-collinear points are selected on the conveyor belt 3 to establish a coordinate system of the working table 1. Firstly, the robot master 5 controls the industrial robot 2 to move to a point P1, records the world coordinates of the industrial robot 2 at a point P1, records the world coordinates of points P2/P3 by using the same method, and knows that P1/P2/P3 can obtain a transformation matrix from a world coordinate system to a workbench 1 coordinate system. The positive Y-axis direction of the table 1 coordinate system is defined as the direction of movement along the conveyor 3. The coordinate calibration of the vision system 6 and the industrial robot 2 are both based on the coordinate system of the working table 1. Further, the conveying direction of the conveyor belt can be designated as the Y-axis and the direction perpendicular to the conveying direction of the conveyor belt as the X-axis for convenience of calculation.
S12, calibrating the visual field of the visual system 6 by using a 9-point method, and determining the transformation relation between the pixel position in the visual system 6 and the coordinate system of the workbench 1;
as shown in fig. 6, in the coordinate system of the table 1, the industrial robot 2 is sequentially moved to 9 points on the calibration board, and coordinate values (x, y) in the coordinate system of the table 1 corresponding to the 9 points are recorded. The camera 12 takes a picture of the calibration plate, marks the pixel positions of the 9 points in the picture, enables the coordinate values of the 9 positions under the coordinate system of the workbench 1 to correspond to the pixel positions of the 9 points in the picture one by one, and can calculate the conversion relation between the shooting visual field and the coordinate system of the workbench 1. Therefore, each pixel point in the shooting field corresponds to a coordinate value in the coordinate system of the workbench 1.
Returning to fig. 3.
S20, the vision system 6 acquires contour information of the recognition template of the object, and generates and records a target position set at a specified pixel position within the contour information based on the contour information.
Before grabbing the object, a recognition template for the vision system 6 to recognize is first made, which has the same contour as the object, and then the object is placed in the shooting field of the camera 12 to shoot an image. The contour information of the object may then be calculated by the image calculator 13, or manually circled on the image calculator 13.
The target position is then moved to the specified pixel position set within the contour information by manually moving the target position within the image calculator 13. The image calculator 13 records the contour information and binds target position information on the contour information.
S30, starting a period;
s31, the robot main control 5 intermittently sends a photographing command to the vision system 6 based on the position signal of the conveyor belt 3 output by the encoder 4;
the robot main control 5 obtains the moving distance of the conveyor belt 3 by calculating through obtaining the position value output by the encoder 4, and when the moving distance of the conveyor belt 3 reaches the specified distance, the robot main control 5 sends a photographing command to the vision system 6.
S21, the vision system 6 shoots and obtains the image information of the shooting visual field;
s22, the visual system 6 identifies the shot image information and obtains the contour information which is the same as the identification template in the image information;
s23, the vision system 6 obtains the target position at the appointed pixel position of the contour information through calculation;
s24, the vision system 6 sends the target position to the robot master 5.
S32, the robot master control 5 acquires the target position of the object shot and identified by the vision system 6 and the position signal of the conveyor belt 3 output by the corresponding encoder 4 and records the position signal into a detection queue;
the vision system 6 receives the shooting command, and shoots to obtain the image information in the shooting view field; the image computer identifies the shot image information and acquires the contour information which is the same as the identification template in the image information; when the same contour information is found, the image computer obtains the target coordinate value at the specified pixel position of the contour information through calculation. And then the image computer sends the coordinate value of the target to the robot main control 5, and meanwhile, the robot main control 5 acquires the position signal of the conveyor belt 3 output by the encoder 4, and records the position of the target and the position signal of the conveyor belt 3 output by the corresponding encoder 4 into a detection queue.
It should be noted that if a plurality of contour information identical to the identification template exists in one piece of image information, the image computer obtains a plurality of target positions through calculation, and transmits the target positions to the robot main control 5. The positions of a plurality of targets are recorded in the detection queue of the robot master control 5 at the same time, and the detection queue of the robot master control 5 is set at the positions of the targets when recording the positions of the targets.
S33, the robot master control 5 judges whether target position data exist in the detection queue, if yes, the step S34 is executed, and if not, the step S36 is not executed;
s34, the robot main control 5 judges whether the target position in the head of the queue moves to the working range of the industrial robot 2, if so, the step S35 is executed, and if not, the step S36 is not executed;
the working range of the industrial robot 2 is a preset coordinate interval; the target position is updated in real time following the movement of the conveyor belt 3. The robot main control 5 judges whether the target position enters the working range of the industrial robot 2 by judging whether the target position belongs to the coordinate interval of the working range of the industrial robot 2.
S35, the robot main control 5 controls the industrial robot 2 to grab the target position in the head of the queue;
as shown in fig. 7, the industrial robot 2 grasping step of step S35 includes:
s351, obtaining the industrial robot 2 and the first target position of the queue;
s352, judging whether the target position of the head of the queue is out of the working range of the industrial robot 2, if so, skipping to the step S353, and if not, skipping to the step S354;
if the target position is not within the working range of the industrial robot 2 during the gripping process, this indicates that the object has been removed from the working range of the industrial robot 2 by the conveyor belt 3.
S353, moving the target position of the first position of the queue out of the queue, abandoning the capture, and jumping to the step S40;
s354, calculating the position difference between the industrial robot 2 and the target, and obtaining a reference speed based on the position difference;
s355, acquiring a reference speed of the industrial robot 2 based on the reference speed and the output speed of the encoder 4;
with reference to fig. 8, the method for calculating the reference velocity of the industrial robot 2:
the following symbols are defined:
TABLE 1 symbol definition Table
In step S354, the reference speed vp (i) is calculated as follows:
from B, D1 and D2, the current position C of the target object is found: c (i) = B + D2(i) -D1,
distance of industrial robot from target object: rAC (i) = C (i) — A (i),
reference speed output by position P controller: vp (i) = rac (i) = KPp.
In step S355 the reference speed vr (i) of the industrial robot is calculated as follows:
deviation value of reference speed and conveyor belt speed output by position P controller: vrer (i) = vt (i) -vp (i);
cumulative error of velocity: vrersum (i) += vrer (i);
output of reference speed of robot: vr (i) = KVp · verr (i) + KVi · verrsum (i).
S356, judging whether the distance between the industrial robot 2 and the target position and the speed difference between the reference speed of the industrial robot 2 and the output speed of the encoder 4 are both smaller than preset values, if so, executing a step S357, and if not, executing a step S40;
and S357, executing the grabbing action by the industrial robot 2, and removing the target position at the head of the queue from the queue.
The grabbing process comprises the following steps: the robot main control 5 controls the industrial robot 2 to keep the same moving speed as the object, lowers the Z axis of the robot body 17, and opens the electromagnetic valve to enable the suction nozzle to be adsorbed at the target position of the object; and then the robot main control 5 controls the industrial robot 2 to move to the position where the object is placed, and the electromagnetic valve is closed, so that the suction nozzle is adsorbed on the object and placed at the place where the object is placed.
S36, the robot main control 5 controls the industrial robot 2 to move back to a standby point;
the position of the standby point is designed to reduce the distance between the industrial robot 2 and the article entering the working range of the industrial robot 2 when the industrial robot 2 does not perform the work of gripping the object. The stand-by point is thus arranged on the side of the working range of the industrial robot 2 close to the entry of the conveyor belt.
S40, proceed to the next cycle.
It is above only the utility model discloses a preferred embodiment, the utility model discloses a scope of protection does not only confine above-mentioned embodiment, the all belongs to the utility model discloses a technical scheme under the thinking all belongs to the utility model discloses a scope of protection. It should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.