CN108972343B - Two-degree-of-freedom grinding and polishing contact force control method and system - Google Patents
Two-degree-of-freedom grinding and polishing contact force control method and system Download PDFInfo
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Abstract
The invention belongs to the field of grinding and polishing contact force control, and particularly discloses a two-degree-of-freedom grinding and polishing contact force control methodThe method comprises collecting angle change information and x-direction force information F of two-degree-of-freedom force control device relative to world coordinate systemx1And y-direction force information Fy1(ii) a According to angle change information pair Fx1And Fy1Performing gravity compensation to obtain FxAnd FyAccording to FxAnd FyCalculating the positive contact pressure Fc(ii) a F is to becComparing the expected contact force to obtain a force error, calculating the speed control quantity of the grinding head in the contact force direction according to the force error, and calculating the tangential speed control quantity of the grinding head; obtaining x-direction speed control quantity and y-direction speed control quantity according to the speed control quantity and the tangential speed control quantity of the grinding head in the contact force direction; the actual contact force of the grinding head and the part is enabled to reach the expected contact force under the control of the x-direction speed control quantity and the y-direction speed control quantity. The invention can realize the control of contact force in the two-degree-of-freedom grinding and polishing processing, ensures the stable grinding and polishing processing and has high processing efficiency.
Description
Technical Field
The invention belongs to the field of grinding and polishing contact force control, and particularly relates to a two-degree-of-freedom grinding and polishing contact force control method and system.
Background
With the development of science and technology, the application of the complex curved surface in the fields of aerospace, automobiles, ships and the like is increasingly wide. The curved surfaces cannot be composed of primary analytical curved surfaces, and an accurate analytical solution of a free complex curved surface is difficult to obtain, so that the finish machining of the complex curved surface is a manufacturing difficult problem to be solved urgently.
At present, the surface finish machining of the free-form curved surface mainly comprises a numerical control polishing technology and a manual grinding mode. The numerical control polishing technology has the defects of high price and low processing efficiency of the numerical control machine, the labor intensity of manual polishing is high, the processing efficiency is low, the working environment is severe, meanwhile, the precision of a workpiece is greatly influenced by the proficiency of the technology of the worker, and the surface quality of the workpiece is severely restricted. Compared with the traditional processing mode, the robot system has the advantages of good flexibility, strong universality, easiness in expansion and the like, so that the research on the constant-force grinding and polishing system and method for clamping the end effector by the robot is very necessary.
The constant force grinding and polishing system and method need to realize contact force control, mainly comprises single-degree-of-freedom contact force control and two-degree-of-freedom contact force control, the single-degree-of-freedom contact force control method has the problems of long time consumption and easiness in over-polishing, and the two-degree-of-freedom contact force control can greatly improve grinding and polishing efficiency and is more favorable for avoiding the over-polishing problem to a certain extent. However, few studies have been made on how to effectively control the two-degree-of-freedom contact force, and further studies are necessary to effectively control the two-degree-of-freedom contact force in real time.
Disclosure of Invention
Aiming at the defects or improvement requirements of the prior art, the invention provides a two-degree-of-freedom grinding and polishing contact force control method and a two-degree-of-freedom grinding and polishing contact force control system, which realize the control of the contact force in the two-degree-of-freedom grinding and polishing process through force position decoupling, ensure that the grinding and polishing contact force is always equal to the expected contact force, ensure the stable and compliant grinding and polishing process, improve the processing efficiency and can stably and efficiently grind and polish parts.
In order to achieve the above object, according to one aspect of the present invention, a two-degree-of-freedom polishing contact force control method is provided, which includes the following steps:
s1 collecting angle change information of the two-degree-of-freedom force control device for realizing grinding and polishing relative to the world coordinate system and x-direction force information F of the two-degree-of-freedom force control devicex1And y-direction force information Fy1；
S2, gravity compensation is carried out on the x-direction force information and the y-direction force information according to the angle change information, and compensated x-direction force information F is obtainedxAnd y-direction force information FyAccording to FxAnd FyCalculating to obtain the contact positive pressure Fc；
S3 is exposed to positive pressure FcComparing with preset expected contact force to obtain force error, and calculating out the grinder according to the force errorCalculating the speed control quantity of the grinding head in the contact force direction according to the position information of the grinding head in the x direction and the position information of the grinding head in the y direction;
s4, decomposing the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction into the x direction and the y direction of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x direction speed control quantity and the y direction speed control quantity of the two-degree-of-freedom force control device;
s5, the motion control of the two-degree-of-freedom force control device in the x and y directions is realized by using the x and y direction speed control quantity of the two-degree-of-freedom force control device, so that the actual contact force of the grinding head and the part reaches the expected contact force.
As a further preference, gravity compensation is carried out in particular in the following manner:
(1) calculating the compensation quantity of the two-degree-of-freedom force control device in the x direction and the y direction:
Fx2＝G0×sin(γ)
Fy2＝G0×cos(γ)cos(β)
wherein, Fx2Compensation quantity in x direction for two-degree-of-freedom force control device, Fy2Compensation in the y-direction of a two-degree-of-freedom force control device, G0Gamma is the rotation angle of the two-freedom-degree force control device relative to the X axis of the world coordinate system, and β is the rotation angle of the two-freedom-degree force control device relative to the Y axis of the world coordinate system;
(2) calculating compensated x-direction force information FxAnd y-direction force information Fy：
Fx＝Fx1-Fx2
Fy＝Fy1-Fy2。
As further preferred, the positive pressure F is contactedcCalculated using the following formula:
wherein the content of the first and second substances,
μ is positive contact pressure FcWith tangential grinding and polishing force FfCoefficient of (d) between.
As a further preferred, the speed control quantity of the grinding head in the contact force direction is calculated by adopting the following formula:
wherein u is1(t) is the speed control quantity of the grinding head in the contact force direction, KpIs a proportionality coefficient, KiIs the integral coefficient, KdFor the coefficient of the differential term, e (t) is the force error, e (t) is the desired contact force FdPositive contact pressure FcAnd t is time.
As a further preferred, the grinding head tangential speed control quantity is calculated by adopting the following formula:
wherein u is2(t) is the tangential velocity control of the grinding head, KpIs a proportionality coefficient, KiIs the integral coefficient, KdA differential coefficient, p (t) position error, p (t) cos (α) × Yp-sin(α)×Xp，XpAs positional information of the grinding head in the x-direction, YpThe position information of the grinding head in the y direction, t is time, α is FxAnd FcThe included angle of (a).
Preferably, the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction are decomposed to the x and y directions of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x and y direction speed control quantities of the two-degree-of-freedom force control device, and the method specifically comprises the following steps:
ux＝cos(α)×u1(t)-sin(α)×u2(t)
uy＝cos(α)×u1(t)+cos(α)×u2(t)
wherein u isxFor x-direction velocity control quantity, uyControlling the quantity for the y-direction speed，u1(t) is the speed control quantity of the grinding head in the contact force direction, u2(t) is the tangential velocity control amount of the grinding head, α is FxAnd FcThe included angle of (a).
Further preferably, α is calculated using the following formula:
preferably, the gravity-compensated force is compared with a preset force, and if the absolute value of the gravity-compensated force is greater than the preset force, the two-degree-of-freedom force control device stops moving; and simultaneously comparing the displacement information of the two-degree-of-freedom force control device in the x direction or the y direction with a preset distance, and stopping the motion of the two-degree-of-freedom force control device if the displacement information is greater than the preset distance.
According to another aspect of the present invention, there is provided a two-degree-of-freedom polishing contact force control system, comprising:
an information acquisition module for acquiring the angle change information of the two-degree-of-freedom force control device relative to the world coordinate system and the x-direction force information F of the two-degree-of-freedom force control devicex1And y-direction force information Fy1；
A gravity compensation module for performing gravity compensation on the x-direction force information and the y-direction force information according to the angle change information to obtain compensated x-direction force information FxAnd y-direction force information Fy；
A positive contact pressure calculation module for calculating the information F according to the compensated x-direction forcexAnd y-direction force information FyCalculating to obtain the contact positive pressure Fc；
Force control module for bringing contact with positive pressure FcComparing the measured value with a preset expected contact force to obtain a force error, and calculating the speed control quantity of the grinding head in the contact force direction according to the force error;
the position control module is used for calculating the tangential speed control quantity of the grinding head according to the position information of the grinding head in the x direction and the position information of the grinding head in the y direction;
the force position decoupling module is used for decomposing the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction to the x direction and the y direction of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x direction speed control quantity and the y direction speed control quantity of the two-degree-of-freedom force control device;
and the two-degree-of-freedom control module is used for realizing the motion control of the x direction and the y direction of the two-degree-of-freedom force control device by utilizing the x direction and the y direction speed control quantity of the two-degree-of-freedom force control device, so that the actual contact force of the grinding head and the part reaches the expected contact force.
As a further preferred option, the system further comprises an overload protection module and an overtravel protection module, wherein the overload protection module is used for comparing the force after gravity compensation with a preset force, and stopping the motion of the two-degree-of-freedom force control device when the absolute value of the force after gravity compensation is greater than the preset force; the overtravel protection module is used for comparing the displacement information of the two-freedom-degree force control device in the x direction or the y direction with the preset distance and stopping the movement of the two-freedom-degree force control device when the displacement information is larger than the preset distance.
Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:
1. the invention can realize the real-time control of the grinding and polishing contact force with two degrees of freedom, so that the grinding and polishing contact force is always equal to the expected contact force to polish and grind the part under the expected contact force, thereby ensuring the stable and compliant grinding and polishing process, improving the processing efficiency, and avoiding the problems of over-polishing and uneven grinding and polishing of the workpiece caused by over-large grinding and polishing force or over-long grinding and polishing time in the grinding and polishing process.
2. The invention obtains force error by comparing the contact positive pressure with expected contact force, calculates the speed control quantity of the grinding head in the contact force direction according to the force error, and simultaneously calculates the tangential speed control quantity of the grinding head according to the x-direction position information and the y-direction position information of the two-freedom-degree force control device, so that the x-direction and y-direction speed control quantities of the two-freedom-degree force control device are obtained by decoupling the speed control quantities in the two directions, and the motion control of the grinding head is realized under the control of the speed control quantities in the two directions, thereby realizing the control of the tangential position of the grinding head and the contact force control (namely grinding and polishing contact force) of the grinding head and a part.
3. According to the invention, through gravity compensation processing, noise information (information except contact force, namely gravity information) in the force information is removed, so that the compensated information is only information related to the contact force, the accuracy of control is ensured, and the precision and quality of part grinding and polishing are improved.
4. The invention also provides the positive contact pressure, the speed control quantity of the grinding head in the contact force direction, the tangential speed control quantity of the grinding head, the x-direction and y-direction speed control quantity of the two-degree-of-freedom force control device and FxAnd FcThe specific processing formulas of the parameters such as the included angle and the like can realize the quick and effective solution and acquisition of each parameter.
5. The invention also provides overload protection and overtravel protection, so that the overload protection prevents the instantaneous acting force from being overlarge and exceeding the range of the force sensor to damage the force sensor, and the overtravel protection prevents the two-degree-of-freedom motion platform from being blocked due to overtravel.
Drawings
FIG. 1 is a schematic structural diagram of a two-degree-of-freedom force control device;
FIG. 2 is a flowchart of a method for controlling a contact force of polishing with two degrees of freedom according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating a stress applied to a part during a process of contacting the part by the two-degree-of-freedom force control device according to the embodiment of the present invention;
fig. 4 is a schematic view of a blisk according to an embodiment of the present invention.
The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: the method comprises the following steps of 1-connecting flange, 2-two-degree-of-freedom motion platform, 3-force sensor, 4-grinding head motor, 5-grinding head, 7-inclination angle sensor, 8-servo motor and 9-blisk profile.
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. 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.
For the convenience of the description of the two-degree-of-freedom contact force control method, firstly, the structure of the two-degree-of-freedom force control device for realizing grinding and polishing is simply described, the structure is an existing conventional structure, as shown in fig. 1, the two-degree-of-freedom force control device comprises a connecting flange 1, a two-degree-of-freedom motion platform 2, a force sensor 3, a grinding head motor 4, a grinding head 5, an inclination angle sensor 7 and a servo motor 8, the whole two-degree-of-freedom force control device is connected to the tail end of a robot or a machine tool through the connecting flange 1, the two-degree-of-freedom motion platform 2 is connected with the connecting flange 1, two servo motors 8 are arranged on the two-degree-of freedom motion platform 2, the force sensor 3 is connected with the two-degree-of-freedom motion platform 2 and the grinding head motor 4, the grinding head, two ball screws are arranged in an orthogonal mode, one servo motor controls the two-degree-of-freedom motion platform 2 to do linear motion along the x direction, the other servo motor controls the two-degree-of-freedom motion platform 2 to do linear motion along the y direction, and the motion of the two-degree-of-freedom motion platform 2 in the xy plane drives the grinding head 5 to move in the xy plane.
Fig. 2 is a flowchart of a two-degree-of-freedom polishing contact force control method provided in an embodiment of the present invention, and as shown in fig. 2, the method includes the following steps:
s1 a robot or a machine tool drives a two-degree-of-freedom force control device to move so as to drive a grinding head to contact with a part to be ground and polished, and angle change information gamma and β of the two-degree-of-freedom force control device relative to a world coordinate system is acquired through an inclination angle sensor 7 in the moving process, wherein gamma is the rotating angle of the two-degree-of-freedom force control device relative to an X axis of the world coordinate system, β is the rotating angle of the two-degree-of-freedom force control device relative to a Y axis of the world coordinate system, the world coordinate system is preset and is always kept unchanged, the relative position of the two-degree-of-freedom force control device and the world coordinate system is changed in the moving process of the two-degree-of freedom force control device, and in the process, the inclination angleRotating the angle; the x-direction force information F of the two-freedom-degree force control device is obtained through the measurement of the force sensor 3x1And y-direction force information Fy1(ii) a The force sensor 3 is arranged on the two-degree-of-freedom force control device, in the motion process of the two-degree-of-freedom force control device, the force sensor 3 can measure the force in three directions of xyz, as shown in fig. 1, the direction of x is the direction of horizontal left and right movement of the two-degree-of-freedom motion platform under the drive of one servo motor 8, the direction of y is the direction of horizontal front and back movement of the two-degree-of-freedom motion platform under the drive of the other servo motor 8, and the direction of z is vertical to the xy plane;
s2 according to the angle change information to the x-direction force information Fx1And y-direction force information Fy1Performing gravity compensation to obtain compensated x-direction force information FxAnd y-direction force information FySpecifically, gravity compensation is performed in the following manner:
s21, calculating the compensation quantity of the two-degree-of-freedom force control device in the x direction and the y direction:
Fx2＝G0×sin(γ)
Fy2＝G0×cos(γ)cos(β)
wherein, Fx2Compensation quantity in x direction for two-degree-of-freedom force control device, Fy2Compensation in the y-direction of a two-degree-of-freedom force control device, G0Gamma is the rotation angle of the two-freedom-degree force control device relative to the X axis of the world coordinate system, and β is the rotation angle of the two-freedom-degree force control device relative to the Y axis of the world coordinate system;
s22 calculating compensated x-direction force information FxAnd y-direction force information Fy：
Fx＝Fx1-Fx2
Fy＝Fy1-Fy2；
Then, according to FxAnd FyCalculating to obtain the contact positive pressure Fc(force normal to the point of polishing contact):
wherein, as shown in FIG. 3, FaIs FxAnd FyIs also in contact with positive pressure FcWith tangential grinding and polishing force Ff(tangential force at the point of contact of the polish),
μ is positive contact pressure FcWith tangential grinding and polishing force FfThe coefficient between (a) and (b), which is identified according to the polishing experiment, is generally 0.3;
s3 is exposed to positive pressure FcComparing the measured value with a preset expected contact force to obtain a force error, calculating the speed control quantity of the grinding head in the contact force direction according to the force error, and calculating the tangential speed control quantity of the grinding head according to the position information of the grinding head in the x direction and the position information of the grinding head in the y direction, wherein the position information of the grinding head in the x direction and the position information of the grinding head in the y direction are directly obtained through an encoder on a servo motor;
specifically, the speed control quantity of the grinding head in the contact force direction is calculated by adopting the following formula:
first, the desired contact force is compared with the contact positive pressure FcObtaining a force error e (t):
e(t)＝Fd-Fc
wherein, FdTo the desired contact force, e (t) is the force error;
then, the speed control quantity of the grinding head in the contact force direction is calculated:
wherein u is1(t) is the speed control quantity of the grinding head in the contact force direction; kpThe value range is 0.005-0.015; kiThe value range is 0.005-0.015 for integral coefficient; kdIs a differential term coefficient and takes the value of 0; t is time.
Specifically, the following formula is adopted to calculate the tangential speed control quantity of the grinding head:
first, a grinding head tangential position error p (t) is calculated:
p(t)＝cos(α)×Yp-sin(α)×Xp
wherein, XpAs positional information of the grinding head in the x-direction, YpPosition information of the grinding head in the y direction, p (t) position error;
then, the speed control quantity of the grinding head in the contact force direction is calculated:
wherein u is2(t) is the speed control quantity of the grinding head in the contact force direction; kpThe value range is 0.01-0.06; kiThe value range is 0.01-0.06 for integral coefficient; kdIs a differential term coefficient and takes the value of 0; t is time.
S4, decomposing the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction to the x direction and the y direction of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x-direction and y-direction speed control quantity of the two-degree-of-freedom force control device, which specifically comprises the following steps:
ux＝cos(α)×u1(t)-sin(α)×u2(t)
uy＝cos(α)×u1(t)+cos(α)×u2(t)
wherein u isxFor two-degree-of-freedom force control device x-direction speed control quantity, uyFor two-degree-of-freedom force control device y-direction speed control quantity, u1(t) is the speed control quantity of the grinding head in the contact force direction, u2(t) is the tangential velocity control amount of the grinding head, α is FxAnd FcThe angle of,
theta is FxAnd FaDelta is FcAnd FaThe included angle between them;
s5 uses the x and y speed control of the two-degree-of-freedom force control device to realize the motion control of the x and y directions of the two-degree-of-freedom force control device,thereby realizing the tangential direction of the grinding head (namely the tangential direction of the grinding and polishing contact point, F in figure 3)fDirection) of the grinding head and the contact force, so that the actual contact force of the grinding head and the part reaches the expected contact force, namely, the two servo motors 8 for driving the two-degree-of-freedom force control device to move along the x direction and the y direction move under the control of the corresponding x direction and y direction speed control quantity, so that the position of the grinding head and the contact force of the grinding head and the part are adjusted, the actual contact force of the grinding head and the part is equal to the expected contact force, and the effective control of the two-degree-of-freedom contact force is realized.
Preferably, in order to ensure the accuracy of the force sensor test, the force sensor is subjected to zero setting under no-load conditions before the contact force control, so that the force measured by the force sensor in the contact force control process is the resultant force of gravity and the contact force, and the remaining force is the force related to the contact force after gravity compensation, so as to ensure the accuracy of the contact force test.
Further, the force after gravity compensation (i.e., F)xAnd Fy) Comparing with a preset force, stopping grinding head movement if the absolute value of the force after gravity compensation is larger than the preset force, simultaneously comparing the displacement in the x direction and the y direction (the specific displacement is directly obtained by an encoder on a servo motor) in the two-degree-of-freedom force control device with a preset distance, stopping grinding head movement if the absolute value is larger than the preset distance to realize force overload protection and position overtravel protection, further preventing instantaneous acting force from being too large to damage a force sensor and preventing the two-degree-of-freedom motion platform from overtravel and being stuck, wherein the force overload protection (namely the preset force) is set according to the measuring range of the force sensor, the position overtravel protection (namely the preset distance) is set according to the journey of the two-degree-of freedom motion platform, for example, the preset force is 30N, and when F is greater than the absolute value of the forcexOr FyIf the number of the force sensors exceeds 30N, the force sensors are possibly damaged due to the fact that the measuring range of the force sensors is exceeded, the two-freedom platform stops moving, and when F is larger than 30N, the force sensors are possibly damagedxOr FyIf the number of the force sensors is less than or equal to 30N, the force sensors cannot exceed the measuring range, and the two-degree-of-freedom platform works normally; for example, the preset distance is 20mm, and when the x-direction displacement or the y-direction displacement in the two-degree-of-freedom force control device is larger than 20mm, the two-degree-of-freedom motion is indicatedThe movable platform is possibly blocked due to over travel, the motion of the two-freedom-degree platform is stopped at the moment, and when the x-direction displacement or the y-direction displacement in the two-freedom-degree force control device is less than or equal to 20mm, the travel of the two-freedom-degree motion platform cannot be exceeded, and the two-freedom-degree platform works normally at the moment. In addition, the force signals in two directions after gravity compensation are filtered to filter noise.
As shown in fig. 4, a two-degree-of-freedom contact force control method for blisk polishing will be described in detail, taking blisk polishing and lapping as an example.
Firstly, a grinding head is sleeved with an abrasive belt ring, a robot controls the grinding head 5 to extend into the space between blisk profiles 9, the expected contact positive pressure between a two-degree-of-freedom force control device and the blisk profiles 9 is 5N, the initial value of α is 5.4rad when a workpiece is not contacted, the threshold value set in force overload protection is 30N, the threshold value set in position overtravel protection is 20mm, the grinding head moves towards the blisk profiles 9 before the blisk profiles 9 are not contacted, an inclination angle sensor 7 collects the angle variation gamma and β of the two-degree-of-freedom force control device relative to a world coordinate system, and a force sensor 3 collects the x-direction force information F of the two-degree-of-freedom force control device in the grinding and polishing processx1And y-direction force information Fy1Feeding back the signal obtained by the test to the controller, and utilizing the obtained inclination angle information to the x-direction force information Fx1And y-direction force information Fy1Performing gravity compensation, and identifying positive contact pressure F according to positive contact pressure identification algorithmc(ii) a Comparing the expected contact force with the identified contact positive pressure to obtain a force error, then transmitting the force error to a force control module in the controller, and calculating the speed control quantity of the grinding head in the contact force direction according to the force error through a force control algorithm; transmitting displacement signals of two servo motors of the two-degree-of-freedom force control device to a position control module in a controller, and calculating the tangential speed control quantity of a grinding head 5 in the two-degree-of-freedom force control device in the grinding and polishing process; the controller decomposes the speed control quantity and the tangential speed control quantity of the grinding head in the contact force direction into the motion directions of two servo motors of the two-degree-of-freedom force control device through a decoupling matrix according to the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction, and the speed control quantities are used as speed control instructions of the two servo motors, so that the purpose of realizing the speed control of the twoAnd simultaneously controlling the contact force and the tangential position of the grinding head, so that the grinding head is attached to the blisk profile 9 with expected contact force, and then the grinding head motor 4 drives the grinding head to move at a certain rotating speed so as to polish the blisk profile with the expected contact force. The robot drives the two-degree-of-freedom force control device to move along the blisk profile 9 in a planned path, and the grinding head is always attached to the blisk profile and keeps constant contact positive pressure to perform constant-pressure polishing through control of contact force in the moving process.
The invention realizes the control of the contact force in the two-degree-of-freedom grinding and polishing processing through force position decoupling, can realize the simultaneous control of the contact force and the tangential position of the grinding head when the two-degree-of-freedom force control grinding head contacts a part, ensures the grinding and polishing processing process with stable compliance, improves the processing efficiency, avoids the problems of workpiece over-polishing, uneven grinding and polishing and the like caused by overlarge grinding and polishing force or overlong grinding and polishing time in the grinding and polishing process, and is suitable for any two-degree-of-freedom force control device.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A two-degree-of-freedom grinding and polishing contact force control method is characterized by comprising the following steps:
s1 collecting angle change information gamma and β of the two-degree-of-freedom force control device for realizing grinding and polishing relative to a world coordinate system and x-direction force information F of the two-degree-of-freedom force control devicex1And y-direction force information Fy1Wherein gamma is the rotation angle of the two-degree-of-freedom force control device relative to the X axis of the world coordinate system, and β is the rotation angle of the two-degree-of-freedom force control device relative to the Y axis of the world coordinate system;
s2, gravity compensation is carried out on the x-direction force information and the y-direction force information according to the angle change information, and compensated x-direction force information F is obtainedxAnd y-direction force information FyAccording to FxAnd FyCalculating to obtain the contact positive pressure Fc；
S3 is exposed to positive pressure FcComparing the measured value with a preset expected contact force to obtain a force error, calculating the speed control quantity of the grinding head in the contact force direction according to the force error, and calculating the tangential speed control quantity of the grinding head according to the position information of the grinding head in the x direction and the position information of the grinding head in the y direction;
s4, decomposing the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction into the x direction and the y direction of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x direction speed control quantity and the y direction speed control quantity of the two-degree-of-freedom force control device;
s5, the motion control of the two-degree-of-freedom force control device in the x and y directions is realized by using the x and y direction speed control quantity of the two-degree-of-freedom force control device, so that the actual contact force of the grinding head and the part reaches the expected contact force.
2. The contact force control method for two-degree-of-freedom polishing and grinding as claimed in claim 1, wherein the gravity compensation is performed by adopting the following method:
(1) calculating the compensation quantity of the two-degree-of-freedom force control device in the x direction and the y direction:
Fx2＝G0×sin(γ)
Fy2＝G0×cos(γ)cos(β)
wherein, Fx2Compensation quantity in x direction for two-degree-of-freedom force control device, Fy2Compensation in the y-direction of a two-degree-of-freedom force control device, G0The grinding head motor is connected with the force sensor and the gravity of the grinding head;
(2) calculating compensated x-direction force information FxAnd y-direction force information Fy：
Fx＝Fx1-Fx2
Fy＝Fy1-Fy2。
3. The contact force control method for two-degree-of-freedom polishing and grinding as claimed in claim 1 or 2, characterized in that the positive contact pressure FcCalculated using the following formula:
wherein the content of the first and second substances,
μ is positive contact pressure FcWith tangential grinding and polishing force FfCoefficient of (d) between.
4. The contact force control method for two-degree-of-freedom polishing and grinding as claimed in claim 1, wherein the velocity control quantity of the grinding head in the contact force direction is calculated by adopting the following formula:
wherein u is1(t) is the speed control quantity of the grinding head in the contact force direction, KpIs a proportionality coefficient, KiIs the integral coefficient, KdFor the coefficient of the differential term, e (t) is the force error, e (t) is the desired contact force FdPositive contact pressure FcAnd t is time.
5. The contact force control method for two-degree-of-freedom polishing and grinding as claimed in claim 1, wherein the tangential velocity control quantity of the grinding head is calculated by adopting the following formula:
wherein u is2(t) is the tangential velocity control of the grinding head, KpIs a proportionality coefficient, KiIs the integral coefficient, KdA differential coefficient, p (t) position error, p (t) cos (α) × Yp-sin(α)×Xp，XpAs positional information of the grinding head in the x-direction, YpThe position information of the grinding head in the y direction, t is time, α is FxAnd FcThe included angle of (a).
6. The two-degree-of-freedom polishing contact force control method according to claim 1, wherein the calculated speed control quantity and tangential speed control quantity of the grinding head in the contact force direction are decomposed to x and y directions of the two-degree-of-freedom force control device through a decoupling matrix to obtain x and y direction speed control quantities of the two-degree-of-freedom force control device, and specifically:
ux＝cos(α)×u1(t)-sin(α)×u2(t)
uy＝cos(α)×u1(t)+cos(α)×u2(t)
wherein u isxFor x-direction velocity control quantity, uyFor the y-direction velocity control quantity, u1(t) is the speed control quantity of the grinding head in the contact force direction, u2(t) is the tangential velocity control amount of the grinding head, α is FxAnd FcThe included angle of (a).
7. The method of controlling contact force of polishing with two degrees of freedom as claimed in claim 1, wherein α is calculated by using the following formula:
8. the contact force control method of two-degree-of-freedom polishing and burnishing according to claim 1, wherein the force after gravity compensation is compared with a preset force, and if the absolute value of the force after gravity compensation is larger than the preset force, the motion of the two-degree-of-freedom force control device is stopped; and simultaneously comparing the displacement information of the two-degree-of-freedom force control device in the x direction or the y direction with a preset distance, and stopping the motion of the two-degree-of-freedom force control device if the displacement information is greater than the preset distance.
9. A two-degree-of-freedom grinding and polishing contact force control system is characterized by comprising:
an information acquisition module for acquiring the angle change information of the two-degree-of-freedom force control device relative to the world coordinate system and the x-direction force information F of the two-degree-of-freedom force control devicex1And y-direction force information Fy1；
Gravity compensation module for angle-dependentThe degree change information carries out gravity compensation on the x-direction force information and the y-direction force information to obtain compensated x-direction force information FxAnd y-direction force information Fy；
A positive contact pressure calculation module for calculating the information F according to the compensated x-direction forcexAnd y-direction force information FyCalculating to obtain the contact positive pressure Fc；
Force control module for bringing contact with positive pressure FcComparing the measured value with a preset expected contact force to obtain a force error, and calculating the speed control quantity of the grinding head in the contact force direction according to the force error;
the position control module is used for calculating the tangential speed control quantity of the grinding head according to the position information of the grinding head in the x direction and the position information of the grinding head in the y direction;
the force position decoupling module is used for decomposing the calculated speed control quantity and the calculated tangential speed control quantity of the grinding head in the contact force direction to the x direction and the y direction of the two-degree-of-freedom force control device through a decoupling matrix to obtain the x direction speed control quantity and the y direction speed control quantity of the two-degree-of-freedom force control device;
and the two-degree-of-freedom control module is used for realizing the motion control of the x direction and the y direction of the two-degree-of-freedom force control device by utilizing the x direction and the y direction speed control quantity of the two-degree-of-freedom force control device, so that the actual contact force of the grinding head and the part reaches the expected contact force.
10. The two-degree-of-freedom polishing contact force control system according to claim 9, further comprising an overload protection module and an overtravel protection module, wherein the overload protection module is configured to compare the gravity-compensated force with a preset force, and stop the movement of the two-degree-of-freedom force control device when an absolute value of the gravity-compensated force is greater than the preset force; the overtravel protection module is used for comparing the displacement information of the two-freedom-degree force control device in the x direction or the y direction with the preset distance and stopping the movement of the two-freedom-degree force control device when the displacement information is larger than the preset distance.
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| CN109773659B (en) * | 2019-02-25 | 2020-07-10 | 华中科技大学 | Overload-prevention intelligent force-control grinding and polishing device and grinding and polishing robot |
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| CN110587485B (en) * | 2019-09-20 | 2020-10-30 | 华中科技大学 | Grinding and polishing contact force real-time planning method and system |
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| CN111843714B (en) * | 2020-06-15 | 2022-02-15 | 华中科技大学 | Three-degree-of-freedom grinding and polishing device and force and position coupling control method thereof |
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| CN112318327A (en) * | 2020-11-12 | 2021-02-05 | 佛山市增广智能科技有限公司 | Automatic polishing platform and polishing method thereof |
| CN113910240A (en) * | 2021-11-10 | 2022-01-11 | 上海景吾智能科技有限公司 | Force-controlled polishing method and system for adjusting speed of robot in real time |
| CN115008344B (en) * | 2022-06-08 | 2024-05-03 | 中国科学院宁波材料技术与工程研究所 | Robot tail end constant force floating device and polishing system |
| CN118123642A (en) * | 2024-05-07 | 2024-06-04 | 华中科技大学 | Two-degree-of-freedom rigid-flexible coupling polishing force control device and decoupling control method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105301964A (en) * | 2015-11-19 | 2016-02-03 | 南京工业大学 | Modal decoupling decentralized control method used for magnetic bearing |
| KR20160132660A (en) * | 2015-05-11 | 2016-11-21 | 마자레도벨렌마나익 | Bean-crusher |
| CN106945040A (en) * | 2017-03-24 | 2017-07-14 | 北京理工大学 | A kind of mechanical arm control algolithm for single-freedom and flexible end |
| CN107598765A (en) * | 2017-10-17 | 2018-01-19 | 华中科技大学 | A kind of full electricity digitlization two-freedom degree force control grinding head device |
| CN108284388A (en) * | 2017-12-26 | 2018-07-17 | 华中科技大学 | A kind of intelligent Force control grinding and polishing apparatus of vision guide |
-
2018
- 2018-07-24 CN CN201810820336.0A patent/CN108972343B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160132660A (en) * | 2015-05-11 | 2016-11-21 | 마자레도벨렌마나익 | Bean-crusher |
| CN105301964A (en) * | 2015-11-19 | 2016-02-03 | 南京工业大学 | Modal decoupling decentralized control method used for magnetic bearing |
| CN106945040A (en) * | 2017-03-24 | 2017-07-14 | 北京理工大学 | A kind of mechanical arm control algolithm for single-freedom and flexible end |
| CN107598765A (en) * | 2017-10-17 | 2018-01-19 | 华中科技大学 | A kind of full electricity digitlization two-freedom degree force control grinding head device |
| CN108284388A (en) * | 2017-12-26 | 2018-07-17 | 华中科技大学 | A kind of intelligent Force control grinding and polishing apparatus of vision guide |
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