阅读说明：本技术 一种螺丝锁付装配工艺控制装置及方法 (Device and method for controlling screw locking assembly process ) 是由 黄国辉 迟杰恒 郭晓彬 段亦非 黄均标 于 2020-06-08 设计创作，主要内容包括：本发明实施例涉及自动装配技术领域,公开了一种螺丝锁付装配工艺控制装置及方法,该装置包括：平面定位模块、下压力控制模块、行为决策模块和速度控制模块,其中,所述下压力控制模块包括：下压力检测子模块以及下压力控制子模块,所述速度控制模块包括速度控制子模块,本发明,采用了下压力检测子模块以及下压力控制子模块实现了在不需要对机器人进行外部改装的情况下,精确地控制Z轴的位置和下压力,可有效提高螺丝锁付的良率,且成本低；对第四电动机的旋转速度进行反馈控制,可提高螺丝锁付过程的稳定性,也可以通过旋转速度的变化来估计螺丝锁付的阶段,进而达到精确控制的目的。(The embodiment of the invention relates to the technical field of automatic assembly, and discloses a device and a method for controlling a screw locking and assembling process, wherein the device comprises the following components: the system comprises a plane positioning module, a lower pressure control module, a behavior decision module and a speed control module, wherein the lower pressure control module comprises: the invention adopts the downward pressure detection submodule and the downward pressure control submodule to accurately control the position of the Z axis and the downward pressure under the condition of not needing to externally modify the robot, thereby effectively improving the yield of screw locking and having low cost; the rotation speed of the fourth motor is subjected to feedback control, so that the stability of the screw locking process can be improved, and the stage of the screw locking can be estimated through the change of the rotation speed, so that the aim of accurate control is fulfilled.)

1. A screw-lock assembly process control apparatus, the apparatus comprising: the device comprises a plane positioning module, a lower pressure control module and a behavior decision module, wherein the plane positioning module comprises:

the first arm is connected to the base station through a joint and is driven to rotate by a first motor;

a first position measurement submodule for measuring a current rotation angle of the first motor;

the first position control submodule is used for performing feedback control according to the current rotation angle of the first motor so as to enable the actual position of the first motor to follow the expected position issued by the behavior decision module;

a second arm connected to a distal end of the first arm, the second arm being rotated by a second motor;

a second position measuring submodule for measuring a current rotation angle of the second motor;

the second position control submodule is used for performing feedback control according to the current rotation angle of the second motor so as to enable the actual position of the second motor to follow the expected position issued by the behavior decision module;

the lower pressure control module includes:

the first shaft is composed of a third motor arranged on the second arm and a ball screw arranged at the tail end of the second arm, and the third motor drives the ball screw to move up and down along the Z axis;

a third position measuring submodule for measuring a current rotation angle of the third motor;

the third position control sub-module is used for performing feedback control according to the current rotation angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module;

the downward pressure detection submodule is used for detecting the downward pressure of the ball screw in the first shaft according to the collected current signal of the third motor;

and the downward pressure control submodule is used for carrying out feedback control according to the downward pressure so as to enable the downward pressure of the first shaft ball screw to follow the expected downward pressure.

2. The screw-down assembly process control device of claim 1, further comprising: a speed control module, wherein the speed control module comprises:

a second shaft which is composed of a fourth motor mounted on the second arm and the ball screw, and the ball screw is driven by the fourth motor to rotate around the Z axis;

a speed measurement submodule for measuring a current rotational speed of the fourth motor;

and the speed control submodule is used for performing feedback control according to the current rotating speed of the fourth motor so as to enable the feedback speed of the fourth motor to follow the expected speed issued by the behavior decision module.

3. The screw-lock assembly process control device according to claim 2, wherein the speed detection submodule is specifically configured to obtain the current rotation speed of the fourth motor by differentiating the feedback position signal.

The rotation speed control submodule is specifically used for controlling the motor according to the deviation between the current rotation speed and the speed instruction value, so that the actual speed of the fourth motor follows the speed instruction value.

4. The screw locking assembly process control device according to claim 1, further comprising a hall current sensor disposed on the third motor, wherein the downforce detection submodule is specifically configured to obtain the downforce detection value by combining the current fed back by the hall current sensor with the first shaft dynamics model;

the lower pressure control sub-module is specifically configured to calculate a lower pressure command value according to a deviation between a position detection value and a position command value of the third motor position detection module, and calculate a current command value of the motor according to a deviation between the lower pressure command value and the lower pressure detection value.

5. The screw-down assembly process control device of claim 1, wherein the device comprises a horizontal articulated robot.

6. A screw locking assembly process control method is characterized by comprising the following steps:

the first shaft is driven by a third motor to enable the ball screw to do up-and-down motion of the Z shaft, and the second shaft is driven by a fourth motor to enable the ball screw to do rotary motion around the Z shaft;

measuring a third motor current for moving the ball screw up and down, and calculating a down force of the ball screw with the third motor current;

performing downward pressure feedback control on the third motor through the downward pressure so that the downward pressure of the ball screw follows the downward pressure instruction value of the behavior decision module;

and measuring the rotating angle of a third motor which enables the ball screw to move up and down, and performing feedback control according to the current rotating angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module.

7. The screw-lock assembly process control method of claim 6, further comprising:

and measuring the rotating speed of a fourth motor which enables the ball screw to rotate, and carrying out feedback control according to the current rotating speed of the fourth motor so that the feedback speed of the fourth motor follows the expected speed issued by the behavior decision module.

Technical Field

The embodiment of the invention relates to the technical field of automatic assembly, in particular to a device and a method for controlling a screw locking and assembling process.

Background

The horizontal multi-joint robot is good at working in a plane area, has the capability of moving up and down along a Z axis, and is suitable for screw assembly on a horizontal plane. Traditional industrial robots are too rigid and can damage the robot body if directly used for assembly easily resulting in the robot colliding with the external environment. The traditional method is that an external sensor and a buffer mechanism are added during screw assembly, or a servo screwdriver is directly added on a robot body for transformation.

Chinese patent application CN201820473851.1 discloses an automated screw assembling apparatus, which satisfies the requirements for downward pressure and rotation speed during screw assembling process by changing the third and fourth joints of the traditional horizontal four-joint robot into servo electric screwdriver. The method needs to be modified on the traditional horizontal robot, the universality of the traditional robot is lost, and the added servo electronic batch increases the mechanism cost of the automatic equipment.

Chinese patent application CN201810177801.3 discloses a screw locking device, which controls the downward pressure when the robot is locked by a pressing spring in the hanging device at the end of the horizontal four-axis robot. The above method provides the downward pressure during locking through the spring, but the downward pressure provided by the method cannot be accurately detected or controlled, and the yield of the screw locking is affected.

In view of the above, a need exists for a control device for a screw locking assembly process that is precisely controllable, easy to pass, and low in cost.

Disclosure of Invention

The technical problem mainly solved by the embodiment of the invention is to provide a device and a method for controlling a screw locking assembly process, which can solve the problems that the existing device for controlling the screw locking assembly process is poor in universality, high in cost or incapable of accurately controlling the assembly down pressure.

In order to solve the above technical problem, in a first aspect, an embodiment of the present invention adopts a technical solution that: there is provided a screw-lock fitting process control apparatus, the apparatus comprising: the device comprises a plane positioning module, a lower pressure control module and a behavior decision module, wherein the plane positioning module comprises:

the first arm is connected to the base station through a joint and is driven to rotate by a first motor;

a first position measurement submodule for measuring a current rotation angle of the first motor;

the first position control submodule is used for performing feedback control according to the current rotation angle of the first motor so as to enable the actual position of the first motor to follow the expected position issued by the behavior decision module;

a second arm connected to a distal end of the first arm, the second arm being rotated by a second motor;

a second position measuring submodule for measuring a current rotation angle of the second motor;

the second position control submodule is used for performing feedback control according to the current rotation angle of the second motor so as to enable the actual position of the second motor to follow the expected position issued by the behavior decision module;

the lower pressure control module includes:

the first shaft is composed of a third motor arranged on the second arm and a ball screw arranged at the tail end of the second arm, and the third motor drives the ball screw to move up and down along the Z axis;

a third position measuring submodule for measuring a current rotation angle of the third motor;

the third position control sub-module is used for performing feedback control according to the current rotation angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module;

the downward pressure detection submodule is used for detecting the downward pressure of the ball screw in the first shaft according to the collected current signal of the third motor;

and the downward pressure control submodule is used for carrying out feedback control according to the downward pressure so as to enable the downward pressure of the first shaft ball screw to follow the expected downward pressure.

Further, the apparatus further comprises: a speed control module, wherein the speed control module comprises:

a second shaft which is composed of a fourth motor mounted on the second arm and the ball screw, and the ball screw is driven by the fourth motor to rotate around the Z axis;

a speed measurement submodule for measuring a current rotational speed of the fourth motor;

and the speed control submodule is used for performing feedback control according to the current rotating speed of the fourth motor so as to enable the feedback speed of the fourth motor to follow the expected speed issued by the behavior decision module.

Further, the device also comprises a Hall current sensor arranged on the third motor, wherein the downward pressure detection submodule is specifically used for obtaining a downward pressure detection value by combining a current fed back by the Hall current sensor with the first shaft dynamic model;

the lower pressure control sub-module is specifically configured to calculate a lower pressure command value according to a deviation between a position detection value and a position command value of the third motor position detection module, and calculate a current command value of the motor according to a deviation between the lower pressure command value and the lower pressure detection value.

Further, the speed detection submodule is specifically configured to obtain a current rotation speed of the fourth motor by differentiating the feedback position signal.

The rotation speed control submodule is specifically used for controlling the motor according to the deviation between the current rotation speed and the speed instruction value, so that the actual speed of the fourth motor follows the speed instruction value.

Further, the apparatus comprises a horizontal multi-joint robot.

In order to solve the above technical problem, in a second aspect, another technical solution adopted in the embodiment of the present invention is: the method for controlling the screw locking assembly process is provided, and comprises the following steps:

the first shaft is driven by a third motor to enable the ball screw to do up-and-down motion of the Z shaft, and the second shaft is driven by a fourth motor to enable the ball screw to do rotary motion around the Z shaft;

measuring a third motor current for moving the ball screw up and down, and calculating a down force of the ball screw with the third motor current;

performing downward pressure feedback control on the third motor through the downward pressure so that the downward pressure of the ball screw follows the downward pressure instruction value of the behavior decision module;

and measuring the rotating angle of a third motor which enables the ball screw to move up and down, and performing feedback control according to the current rotating angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module.

Further, the method further comprises:

and measuring the rotating speed of a fourth motor which enables the ball screw to rotate, and carrying out feedback control according to the current rotating speed of the fourth motor so that the feedback speed of the fourth motor follows the expected speed issued by the behavior decision module.

The embodiment of the invention has the beneficial effects that: different from the prior art, the down pressure detection submodule and the down pressure control submodule are adopted to accurately control the position of the Z axis and the down pressure without externally modifying the robot, so that the yield of screw locking can be effectively improved, and the cost is low; the rotation speed of the fourth motor is subjected to feedback control, so that the stability of the screw locking process can be improved, and the stage of the screw locking can be estimated through the change of the rotation speed, so that the aim of accurate control is fulfilled.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic structural diagram of a screw-fastening assembly process control apparatus applied to an embodiment of the present invention;

fig. 2 is a flowchart of a method for controlling a screw-fastening assembly process according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that, if not conflicted, the various features of the embodiments of the invention may be combined with each other within the scope of protection of the invention. Additionally, while functional block divisions are performed in apparatus schematics, with logical sequences shown in flowcharts, in some cases, steps shown or described may be performed in sequences other than block divisions in apparatus or flowcharts.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Specifically, the embodiments of the present invention will be further explained below with reference to the drawings.

The embodiment of the present invention provides a device for controlling a screw locking assembly process, which is suitable for a multi-joint robot, such as a horizontal multi-joint robot, and the following embodiments are only described by taking the horizontal multi-joint robot as an example, please refer to fig. 1, which shows a schematic structural diagram of the device for controlling the screw locking assembly process, and the device includes but is not limited to: the device comprises a plane positioning module, a lower pressure control module and a behavior decision module, wherein the plane positioning module comprises:

the first arm is connected to the base station through a joint and is driven to rotate by a first motor;

a first position measurement submodule for measuring a current rotation angle of the first motor;

the first position control submodule is used for performing feedback control according to the current rotation angle of the first motor so as to enable the actual position of the first motor to follow the expected position issued by the behavior decision module; the behavior decision module is used for performing feedback control on the plane positioning module, the lower pressure control module and the speed control module according to the current rotation angle or speed of each motor, and is a control module of the horizontal multi-joint robot, and the expected position is a preset position of the horizontal multi-joint robot.

A second arm connected to a distal end of the first arm, the second arm being rotated by a second motor;

a second position measuring submodule for measuring a current rotation angle of the second motor;

the second position control submodule is used for performing feedback control according to the current rotation angle of the second motor so as to enable the actual position of the second motor to follow the expected position issued by the behavior decision module;

the lower pressure control module includes:

the first shaft is composed of a third motor arranged on the second arm and a ball screw arranged at the tail end of the second arm, and the third motor drives the ball screw to move up and down along the Z axis;

a third position measuring submodule for measuring a current rotation angle of the third motor;

the third position control sub-module is used for performing feedback control according to the current rotation angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module;

the downward pressure detection submodule is used for detecting the downward pressure of the ball screw in the first shaft according to the collected current signal of the third motor;

and the downward pressure control submodule is used for carrying out feedback control according to the downward pressure so as to enable the downward pressure of the first shaft ball screw to follow the expected downward pressure.

Specifically, the device further comprises a hall current sensor arranged on the third motor, wherein the lower pressure detection submodule is specifically used for obtaining a lower pressure detection value by combining a current fed back by the hall current sensor with the first shaft dynamics model;

the lower pressure control sub-module is specifically configured to calculate a lower pressure command value according to a deviation between a position detection value and a position command value of the third motor position detection module, and calculate a current command value of the motor according to a deviation between the lower pressure command value and the lower pressure detection value.

In the embodiment of the invention, the lower pressure detection value is an actual lower pressure value obtained by calculation through a first axis dynamic model. The down force instruction value is an adjusted down force instruction calculated by the horizontal multi-joint robot according to the deviation between the current actual position detection and the preset position. The down pressure detection submodule and the down pressure control submodule are adopted to accurately control the position of the Z axis and the down pressure under the condition that the robot is not required to be externally modified, and the yield of screw locking can be effectively improved.

Further, the apparatus further comprises: a speed control module, wherein the speed control module comprises:

a second shaft which is composed of a fourth motor mounted on the second arm and the ball screw, and the ball screw is driven by the fourth motor to rotate around the Z axis;

a speed measurement submodule for measuring a current rotational speed of the fourth motor;

and the speed control submodule is used for performing feedback control according to the current rotating speed of the fourth motor so as to enable the feedback speed of the fourth motor to follow the expected speed issued by the behavior decision module.

Specifically, the speed detection submodule is specifically configured to obtain the current rotation speed of the fourth motor by differentiating the feedback position signal.

The rotation speed control submodule is specifically used for controlling the motor according to the deviation between the current rotation speed and the speed instruction value, so that the actual speed of the fourth motor follows the speed instruction value.

In the embodiment of the invention, the rotation speed of the fourth motor is subjected to feedback control, so that the stability of the screw locking process can be improved, and the stage of the screw locking can be estimated through the change of the rotation speed, thereby achieving the aim of accurate control.

The embodiment of the invention provides a screw locking assembly process control device, which adopts a downward pressure detection submodule and a downward pressure control submodule to accurately control the position of a Z axis and downward pressure under the condition of not needing to externally modify a robot, can effectively improve the yield of the screw locking and has low cost; the rotation speed of the fourth motor is subjected to feedback control, so that the stability of the screw locking process can be improved, and the stage of the screw locking can be estimated through the change of the rotation speed, so that the aim of accurate control is fulfilled.

An embodiment of the present invention provides a method for controlling a screw locking assembly process, which can be executed by the above-mentioned apparatus, and please refer to fig. 2, which shows a flowchart of a method for controlling a screw locking assembly process, and the method includes, but is not limited to, the following steps:

step 201: the first shaft is driven by a third motor to enable the ball screw to move up and down along the Z axis, and the second shaft is driven by a fourth motor to enable the ball screw to rotate around the Z axis.

Step 202: measuring a third motor current for moving the ball screw up and down, and calculating a down force of the ball screw with the third motor current;

step 203: performing downward pressure feedback control on the third motor through the downward pressure so that the downward pressure of the ball screw follows the downward pressure instruction value of the behavior decision module;

step 204: and measuring the rotating angle of a third motor which enables the ball screw to move up and down, and performing feedback control according to the current rotating angle of the third motor so as to enable the actual position of the third motor to follow the expected position issued by the behavior decision module.

Further, the method further comprises:

step 205: and measuring the rotating speed of a fourth motor which enables the ball screw to rotate, and carrying out feedback control according to the current rotating speed of the fourth motor so that the feedback speed of the fourth motor follows the expected speed issued by the behavior decision module.

In the embodiment of the invention, the feedback control is carried out on the rotating positions of the first motor and the second motor, the XY coordinates of the screw can be moved quickly and accurately, the beat and the yield of the screw locking pair are improved, the down pressure detection and the down pressure control are adopted, the position of the Z axis and the down pressure are accurately controlled under the condition that the robot is not required to be externally modified, the yield of the screw locking pair can be effectively improved, and the cost is low; the rotation speed of the fourth motor is subjected to feedback control, so that the stability of the screw locking process can be improved, and the stage of the screw locking can be estimated through the change of the rotation speed, so that the aim of accurate control is fulfilled.

The apparatus provided in the embodiments of the present application can be implemented by the above method, and reference may be made to the apparatus provided in the embodiments of the present application for technical details not described in detail in the embodiments of the present application.

It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.