An electromagnetic drive control system and method for a flexible mechanism

Abstract

An electromagnetic drive control system and method for a flexible mechanism, which has sufficient computing power and performance, enables real-time and effective control of a motion system, can avoid problems such as mechanism wear and lubrication, and extend the service life of the mechanism. Rigid left and right vertical rods are respectively erected on the left and right sides of a base, and a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical rod and the upper and lower ends of the rigid right vertical rod. Each flexible unit is connected to a rigid cross bar or a base through a rigid structure, and a magnetic material is respectively arranged at the left and right ends of the rigid cross bar. The distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, and the distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material. Displacement sensors are respectively arranged near the left magnet and the right magnet.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control systems, and in particular to an electromagnetic drive control system for a flexible mechanism, and a method adopted by the electromagnetic drive control system for the flexible mechanism. Background Art

[0002] With the development of society and technology, the application of new materials, new equipment, new structures and new construction techniques in engineering has led to the development of structures in the three directions of high (deep), light and large. In some fields, the structural form has also changed from the original rigid structure to a flexible structure. The flexible mechanism uses hinges to replace the kinematic pairs of the rigid mechanism, which reduces the number of structures, the weight of the mechanism, the time and cost of processing and assembly, etc. At the same time, it also has the advantages of reducing the gap, friction, wear and lubrication between mechanisms, improving the accuracy and stability of the mechanism, and reducing maintenance costs.

[0003] However, due to the limited range of motion achieved by the deformation of the flexible mechanism, there are axis drift and parasitic errors, and creep and stress relaxation may occur after long-term use, resulting in the problem of reduced instrument accuracy due to long-term use of the instrument. In addition, in the mathematical model, the flexible structure is characterized by low stiffness, high flexibility, and a nonlinear relationship between strain force and deformation displacement. In terms of calculation methods, the problems of flexible structures are also different from those of rigid structures, and the stress size is difficult to calculate. Therefore, it is not easy to achieve more accurate displacement control with traditional mechanical drive methods. Summary of the invention

[0004] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide an electromagnetic drive control system for a flexible mechanism, which has sufficient computing power and performance to enable real-time and effective control of the motion system, avoid problems such as mechanism wear and lubrication, and extend the service life of the mechanism.

[0005] The technical solution of the present invention is: the electromagnetic drive control system for a flexible mechanism comprises: a left magnet (1), a flexible unit (2), a rigid left vertical rod (3), a rigid cross rod (4), a magnetic material (5), a right magnet (6), a displacement sensor (7), a rigid right vertical rod (8), and a base (9);

[0006] A rigid left vertical rod and a rigid right vertical rod are respectively erected on the left and right sides of the base, a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical rod and the upper and lower ends of the rigid right vertical rod, each flexible unit is connected to the rigid cross bar or the base through a rigid structure, a magnetic material is respectively arranged at the left and right ends of the rigid cross bar, a distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, a distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material, and displacement sensors are respectively arranged near the left magnet and the right magnet.

[0007] The invention discloses a rigid left vertical bar and a rigid right vertical bar respectively standing on the left and right sides of a base, a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical bar and the upper and lower ends of the rigid right vertical bar, each flexible unit is connected to the rigid cross bar or the base through a rigid structure, thus forming a simple flexible mechanism similar to the parallelogram deformation principle with the flexible unit as the key transmission part, a magnetic material is respectively arranged at the left and right ends of the rigid cross bar, a distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, and a distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material, displacement sensors are respectively arranged near the left magnet and the right magnet, the flexible mechanism will produce displacement changes after the electromagnetic driving circuit acts, an embedded system is used, a single chip microcomputer is used as the main control of the system, and its sufficient computing power and performance are used to control the motion system in real time and effectively, and the traditional motion control method is replaced by an electromagnetically driven contactless motion control system, which can avoid problems such as mechanism wear and lubrication and extend the service life of the mechanism.

[0008] A working method of an electromagnetic drive control system for a flexible mechanism is also provided, which comprises the following steps:

[0009] (1) Press the arrow key;

[0010] (2) The controller identifies the displacement. When the displacement of the flexible structure deviates, the controller will generate corresponding control actions to eliminate the deviation, making the displacement control more accurate.

[0011] (3) The PWM technology and PID control technology are used to perform closed-loop control on the voltage of the electromagnet, and the duty cycle of the voltage output is accurately calculated by applying the PID algorithm to achieve the purpose of precise voltage regulation;

[0012] (4) Control the on and off of the switch, output pulse signals with different duty ratios, and output corresponding current values;

[0013] (5) The left and right electromagnets are controlled by a relay to work independently, and the displacement is set to positive on the right and negative on the left. When the displacement is positive, the relay does not work, the switch is always in the right position, and the electromagnet on the right is continuously controlled by the single-chip microcomputer; when the displacement is negative, the single-chip microcomputer outputs a signal to the pin of the relay, the relay works, and the switch is in the left position. At this time, the electromagnet on the left works and the electromagnet on the right is turned off, thereby achieving the control purpose;

[0014] (6) The electromagnet acts to attract the flexible unit;

[0015] (7) The flexible unit produces displacement changes;

[0016] (8) The displacement sensor detects the displacement change;

[0017] (9) When the deviation is less than the specified value, the chip controls the voltage so that it does not change, avoiding an infinite loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic structural diagram of an embodiment of a flexible unit of an electromagnetic drive control system for a flexible mechanism according to the present invention.

[0019] Figure 2 It is a front view of an electromagnetic drive control system for a flexible mechanism according to the present invention.

[0020] Figure 3 is a perspective view of an electromagnetic drive control system for a flexible mechanism according to the present invention.

[0021] Figure 4 3 is a displacement variation diagram of the electromagnetic drive control system for the flexible mechanism according to the present invention.

[0022] Figure 5 1 is a schematic structural diagram of another embodiment of a flexible unit of an electromagnetic drive control system for a flexible mechanism according to the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0024] It should be noted that the term "comprises" and any variations in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or equipment.

[0025] like Figure 1 The figure is a diagram of the flexible joint structure of this embodiment. According to structural mechanics, the stiffness calculation formula of the straight circular flexible hinge under the action of force is:

[0026]

[0027] Where:

[0028]

[0029] γ=R / t;

[0030] Where E: elastic modulus of the material, Pa;

[0031] b: Width of the flexible hinge, mm;

[0032] R: cutting radius of the flexible hinge, mm;

[0033] t: thickness of the flexible hinge, mm.

[0034] like Figure 2 , 3 As shown, the electromagnetic drive control system for the flexible mechanism includes: a left magnet 1, a flexible unit 2, a rigid left vertical rod 3, a rigid horizontal rod 4, a magnetic material 5, a right magnet 6, a displacement sensor 7, a rigid right vertical rod 8, and a base 9;

[0035] A rigid left vertical rod and a rigid right vertical rod are respectively erected on the left and right sides of the base, a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical rod and the upper and lower ends of the rigid right vertical rod, each flexible unit is connected to the rigid cross bar or the base through a rigid structure, a magnetic material is respectively arranged at the left and right ends of the rigid cross bar, a distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, a distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material, and displacement sensors are respectively arranged near the left magnet and the right magnet.

[0036] The rigid left vertical rod and the rigid right vertical rod of the present invention are respectively erected on the left and right sides of the base, and a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical rod and the upper and lower ends of the rigid right vertical rod, and each flexible unit is connected to the rigid cross bar or the base through a rigid structure, so as to form a simple flexible mechanism similar to the parallelogram deformation principle with the flexible unit as the key transmission part, and a magnetic material is respectively arranged at the left and right ends of the rigid cross bar, and the spacing distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, and the spacing distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material, and displacement sensors are respectively arranged near the left magnet and the right magnet, and the flexible mechanism will produce displacement changes (such as Figure 4 As shown in the figure, an embedded system is used, and the single-chip microcomputer is used as the main control of the system. Its sufficient computing power and performance are used to control the motion system in real time and effectively. The traditional motion control method is replaced by an electromagnetically driven contactless motion control system, which can avoid problems such as mechanism wear and lubrication and extend the service life of the mechanism.

[0037] Preferably, the magnetic material is an iron sheet or a soft magnet.

[0038] Preferably, the rigid structure is a rigid rod.

[0039] Preferably, a double-layer bracket is provided on the left and right sides of the base, and a displacement sensor is provided at the top of the front layer and the rear layer of each double-layer bracket. With such a structure, displacement measurement can be ensured to be more accurate and reliable.

[0040] Preferably, the flexible unit is a flexible hinge or a thin spring. Figure 5 As shown in FIG. 1 , it is a replacement diagram of the flexible hinge of this embodiment. Due to the limitation of the current processing level in the market, the flexible hinge is precisely processed by CNC machine tools. The minimum thickness t of the flexible hinge is also difficult to be processed to 0.2 mm, and it is difficult to ensure its accuracy. Therefore, the three-dimensional structure of the flexible hinge is difficult to achieve. By forging, the metal raw material is hammered and extruded to be processed into a thin sheet, so the original three-dimensional flexible hinge is replaced with a thin spring sheet.

[0041] Preferably, the flexible unit is made of beryllium bronze, and the rigid left vertical rod, the rigid horizontal rod, the rigid right vertical rod and the base are made of aluminum alloy (with greater rigidity and light texture).

[0042] Preferably, the displacement sensor is a potentiometer sensor.

[0043] Preferably, the left magnet and the right magnet are voltage-stabilized DC electromagnets.

[0044] By using an embedded system, the microcontroller is used as the main control of the system, and its sufficient computing power and performance are used to effectively control the motion system in real time. The drive module is designed as an electromagnetic drive to drive and control the flexible mechanism. Taking the flexible support structure of the moving mirror system as an example, the traditional motion control method is replaced by an electromagnetically driven contactless motion control system.

[0045] Its working principle is: when an iron core is inserted into the solenoid, it is magnetized by the magnetic field of the solenoid. The magnetized iron core becomes a magnet, and the two magnetic fields are superimposed on each other, thereby enhancing the magnetism of the solenoid and generating magnetic force.

[0046] The iron core in the energized solenoid is usually made of ferromagnetic material to make it easier to magnetize. At the same time, in order to make the electromagnet demagnetize immediately when the power is turned off, it is often made of soft iron or silicon steel materials that demagnetize quickly. This type of electromagnet only has magnetic force when the power is turned on, and it demagnetizes immediately when the power is turned off. Using it as the drive module in this design can easily achieve the requirements of instant stop and start, which is in line with the original intention of the design. There are AC electromagnets and DC electromagnets. Considering the stability of control and the cost of power supply, the voltage-stabilized DC electromagnet is more in line with the requirements of this design.

[0047] According to electromagnetism, the formula for calculating the magnetic force of an electromagnet is:

[0048]

[0049] Where φ: working air gap flux, wb;

[0050] B: working air gap magnetic induction intensity, T;

[0051] μ0: vacuum magnetic permeability, its value is 4π*10 -7 wb / A·m;

[0052] S: cross-sectional area, m 2 .

[0053] The controller part of the present invention adopts the high-performance, low-power and low-cost STM32F103 series chip.

[0054] A working method of an electromagnetic drive control system for a flexible mechanism is also provided, which comprises the following steps:

[0055] (1) Press the arrow key;

[0056] (2) The controller identifies the displacement. When the displacement of the flexible structure deviates, the controller will generate corresponding control actions to eliminate the deviation, making the displacement control more accurate.

[0057] (3) The PWM technology and PID control technology are used to perform closed-loop control on the voltage of the electromagnet, and the duty cycle of the voltage output is accurately calculated by applying the PID algorithm to achieve the purpose of precise voltage regulation;

[0058] (4) Control the on and off of the switch, output pulse signals with different duty ratios, and output corresponding current values;

[0059] (5) The left and right electromagnets are controlled by a relay to work independently, and the displacement is set to positive on the right and negative on the left. When the displacement is positive, the relay does not work, the switch is always in the right position, and the electromagnet on the right is continuously controlled by the single-chip microcomputer; when the displacement is negative, the single-chip microcomputer outputs a signal to the pin of the relay, the relay works, and the switch is in the left position. At this time, the electromagnet on the left works and the electromagnet on the right is turned off, thereby achieving the control purpose;

[0060] (6) The electromagnet acts to attract the flexible unit;

[0061] (7) The flexible unit produces displacement changes;

[0062] (8) The displacement sensor detects the displacement change;

[0063] (9) When the deviation is less than the specified value, the chip controls the voltage so that it does not change, avoiding an infinite loop.

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. An electromagnetic drive control system for a flexible mechanism, characterized in that: It includes: Left magnet (1), flexible unit (2), rigid left vertical rod (3), rigid cross rod (4), magnetic material (5), right magnet (6), displacement sensor (7), rigid right vertical rod (8), base (9); A rigid left vertical rod and a rigid right vertical rod are respectively erected on the left and right sides of the base, a flexible unit is respectively arranged at the upper and lower ends of the rigid left vertical rod and the upper and lower ends of the rigid right vertical rod, each flexible unit is connected to the rigid cross bar or the base through a rigid structure, a magnetic material is respectively arranged at the left and right ends of the rigid cross bar, a distance D between the left magnet and the magnetic material at the left end of the rigid cross bar is arranged on the left side of the magnetic material, a distance D between the right magnet and the magnetic material at the right end of the rigid cross bar is arranged on the right side of the magnetic material, and displacement sensors are respectively arranged near the left magnet and the right magnet; The flexible units at the upper ends of the left and right vertical rods are connected to the rigid cross rod through a rigid structure, and the flexible units at the lower ends of the left and right vertical rods are connected to the base through a rigid structure to form a flexible structure based on the parallelogram deformation principle.

2. The electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: The magnetic material is an iron sheet or a soft magnet.

3. The electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: The rigid structure is a rigid rod.

4. The electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: A double-layer bracket is respectively arranged on the left side and the right side of the base, and a displacement sensor is arranged on the top of the front layer and the rear layer of each double-layer bracket.

5. The electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: The flexible unit is a flexible hinge or a thin spring leaf.

6. The electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: The flexible unit is made of beryllium bronze, and the rigid left vertical rod, the rigid horizontal rod, the rigid right vertical rod and the base are made of aluminum alloy.

7. The electromagnetic drive control system for a flexible mechanism according to claim 6, characterized in that: The displacement sensor is a potentiometer type sensor.

8. The electromagnetic drive control system for a flexible mechanism according to claim 7, characterized in that: The left magnet and the right magnet are voltage-stabilized DC electromagnets.

9. The working method of the electromagnetic drive control system for a flexible mechanism according to claim 1, characterized in that: It includes the following steps: (1) Press the arrow key; (2) The controller identifies the displacement. When the displacement of the flexible structure deviates, the controller will generate corresponding control actions to eliminate the deviation, making the displacement control more accurate. (3) The PWM technology and PID control technology are used to perform closed-loop control on the voltage of the electromagnet, and the duty cycle of the voltage output is accurately calculated by applying the PID algorithm to achieve the purpose of precise voltage regulation; (4) Control the on and off of the switch, output pulse signals with different duty ratios, and output corresponding current values; (5) The left and right electromagnets are controlled by a relay to work independently, and the displacement is set to positive on the right and negative on the left. When the displacement is positive, the relay does not work and the switch is always in the right position. The electromagnet on the right is continuously controlled by the microcontroller; when the displacement is negative, the microcontroller outputs a signal to the pin of the relay, the relay works, and the switch is in the left position. At this time, the electromagnet on the left works and the electromagnet on the right is closed, thereby achieving the control purpose; (6) The electromagnet acts to attract the flexible unit; (7) The flexible unit produces displacement changes; (8) The displacement sensor detects the displacement change; (9) When the deviation is less than the specified value, the chip controls the voltage so that it does not change, avoiding an infinite loop.

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