Electric cylinder running speed control method and device based on trajectory planning and storage medium

Abstract

The invention discloses an electric cylinder running speed control method and device based on trajectory planning and a storage medium, and belongs to the technical field of electric cylinders, the method comprises the steps that an initial speed curve of an electric cylinder is obtained, and the initial speed curve comprises a constant speed stage, an elastic stage and a determination stage; the elastic stage comprises a uniform acceleration stage and a uniform deceleration stage; the determination stage comprises an acceleration acceleration stage, an acceleration reduction stage, an acceleration and deceleration stage and a deceleration and deceleration stage; according to the initial working state and the expected working state of the electric cylinder, the assumed operation time of each section in the initial speed curve is obtained; whether an elastic stage and a constant speed stage exist or not is judged, so that a target speed curve and target running time of all the stages in the target speed curve are determined; and based on the target operation time of each section, the target speed curve of the electric cylinder is converted into a rotating speed control signal of a driving motor of the electric cylinder, and control over the electric cylinder is achieved. The method can avoid sudden change of the loading force of the electric cylinder, effectively reduces system vibration, and improves the position control precision of the electric cylinder.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric cylinders, and in particular relates to a method, a device and a storage medium for controlling the running speed of an electric cylinder based on trajectory planning. Background Art

[0002] With the continuous advancement of automation technology, electric cylinders, as a new type of drive device replacing traditional hydraulic cylinders and pneumatic cylinders, have been widely used in the industrial field due to their advantages of high efficiency, precision, and environmental protection. Electric cylinders drive mechanical parts such as screws or racks through motors to achieve linear motion and are widely used in mechanical manufacturing, automated production lines, intelligent control systems and other fields.

[0003] However, in the application of electric cylinders, especially under high speed and high load conditions, speed control accuracy and stability still face some technical bottlenecks. Existing electric cylinder speed control systems usually use traditional PID control algorithms or simple closed-loop control strategies. Although these methods can meet the requirements in some cases, they have the following shortcomings in some high-precision, high-dynamic response applications:

[0004] (1) Response delay and overshoot problems: Traditional PID control systems often show large response delays and overshoots when adjusting speed, especially when the load changes greatly, and cannot achieve ideal speed tracking and rapid adjustment; (2) Insufficient control accuracy: Under complex working conditions, existing speed control methods often cannot ensure the high accuracy and stability of electric cylinder movement. Factors such as load fluctuations and friction changes have greatly reduced the effectiveness of traditional control methods, resulting in a large deviation between actual control and the expected target; (3) Poor adaptability: Many existing electric cylinder speed control methods lack adaptability and cannot automatically adjust control parameters according to different working conditions or environmental conditions, resulting in unstable control effects in different application scenarios; (4) Low energy efficiency: Traditional electric cylinder speed control systems often ignore energy efficiency optimization during operation, resulting in high energy consumption under certain working conditions, especially when the load changes greatly, the efficiency of the control system is low.

[0005] Therefore, in response to these shortcomings, developing a more accurate, stable, intelligent and energy-efficient electric cylinder speed control method has become an urgent need for the development of electric cylinder technology. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method, device and storage medium for controlling the running speed of an electric cylinder based on trajectory planning, which can reduce system vibration and improve the control accuracy of the electric cylinder position.

[0007] The present invention provides the following technical solutions:

[0008] In a first aspect, a method for controlling the running speed of an electric cylinder based on trajectory planning is provided, comprising:

[0009] Step S1: obtaining an initial speed curve of the electric cylinder, wherein the initial speed curve includes a uniform speed section, an elastic stage and a determination stage; the elastic stage includes a uniform acceleration section and a uniform deceleration section; the determination stage includes an acceleration section, a deceleration section, an acceleration and deceleration section and a deceleration and deceleration section;

[0010] Step S2: acquiring the assumed running time of each segment in the initial speed curve according to the initial working state and the expected working state of the electric cylinder;

[0011] Step S3: Determine whether the elastic stage and the uniform speed stage exist respectively. If both exist, the initial speed curve is the target speed curve, and the assumed running time of each stage is the target running time of each stage; if both do not exist, the determination stage is the target speed curve, and the target running time of each stage in the determination stage is obtained according to the target speed curve; if the uniform speed stage exists but the elastic stage does not exist, the uniform speed stage and the determination stage are the target speed curve, and the assumed running time of the uniform speed stage is the target running time of the uniform speed stage, and the target running time of each stage in the determination stage is obtained according to the target speed curve; if the elastic stage exists but the uniform speed stage does not exist, the elastic stage and the determination stage are the target speed curve, and the assumed running time of the elastic stage and the determination stage is the target running time of the elastic stage and the determination stage;

[0012] Step S4: Based on the target running time of each segment, the target speed curve of the electric cylinder is converted into a speed control signal of the electric cylinder driving motor to achieve the running speed control of the electric cylinder.

[0013] Optionally, in step S1, obtaining the initial speed curve of the electric cylinder specifically includes:

[0014] The acceleration curve of the electric cylinder is designed and planned through the quadratic function, and the initial acceleration curve, initial velocity curve and initial displacement curve are obtained by continuous integration of time.

[0015] Optionally, the acceleration curve of the electric cylinder is:

[0016]

[0017] Among them, τ i =tt i-1 , (i=1,2,3…7); j(t) is the acceleration at time t, a m is the expected maximum acceleration, j m is the expected maximum jerk, t1, t2, t3, t4, t5, t6 and t7 are the running end times of the jerk section, uniform acceleration section, deceleration section, uniform speed section, acceleration and deceleration section, uniform deceleration section and deceleration and deceleration section respectively;

[0018] The initial speed curve of the electric cylinder is:

[0019]

[0020] Where v(t) is the velocity at time t, v s is the initial speed of the electric cylinder, v1, v2, v3, v4, v5 and v6 are the speeds at the end of the acceleration section, uniform acceleration section, deceleration section, uniform speed section, acceleration and deceleration section and uniform deceleration section respectively, v m is the expected maximum operating speed of the electric cylinder.

[0021] Optionally, in step S2, the initial working state of the electric cylinder is the initial speed v of the electric cylinder. s The desired working state of the electric cylinder includes the expected maximum operating speed v m , expected maximum acceleration a m 、Expected maximum jerk j m and the expected displacement value S r The assumed running time of each segment in the initial speed curve includes the assumed running time T1 of the acceleration segment, the assumed running time T2 of the uniform acceleration segment, the assumed running time T3 of the deceleration segment, the assumed running time T4 of the uniform speed segment, the assumed running time T5 of the acceleration / deceleration segment, the assumed running time T6 of the uniform deceleration segment and the assumed running time T7 of the deceleration / deceleration segment;

[0022] The assumed running time of each segment in the initial speed curve is obtained by the following formula:

[0023]

[0024]

[0025] T a =T d =T2+2T1

[0026] Among them, SA and T a are the displacement value and total running time of the acceleration phase, SD and T d are the displacement value and total running time in the deceleration phase respectively.

[0027] Optionally, in step S3, the respectively determining whether the elastic stage and the uniform speed segment exist includes determining whether the elastic stage exists and determining whether the uniform speed segment exists;

[0028] The condition for judging whether the elastic stage exists is: If yes, then the elastic phase exists, if no, then the elastic phase does not exist;

[0029] The condition for judging whether a uniform speed segment exists is: SA+SD<S r ; If so, the uniform speed segment exists; if not, the uniform speed segment does not exist.

[0030] Optionally, the step S3 specifically includes: when both the uniform speed stage and the elastic stage exist, the target running time corresponding to the target speed curve is:

[0031]

[0032] When neither the uniform speed segment nor the elastic stage exists, the target running time of each segment corresponding to the target speed curve is:

[0033]

[0034] When the uniform speed segment exists and the elastic stage does not exist, the target running time of each segment corresponding to the target speed curve is:

[0035]

[0036] When the elastic stage exists and the uniform speed stage does not exist, the target running time of each stage corresponding to the target speed curve is:

[0037]

[0038] Among them, T1, T2, T3, T4, T5, T6 and T7 are the assumed running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively; T1', T2', T3', T4', T5', T6' and T7' are the target running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively.

[0039] Optionally, the step S4 specifically includes:

[0040] According to the relationship between the running speed of the electric cylinder and the speed of the driving motor and the target running time of each segment in the target speed curve, the target speed curve is converted into an expected input signal of the speed of the driving motor, and input into the motor speed controller so that the motor speed controller outputs a speed control signal of the driving motor;

[0041] The motor speed controller adopts a double closed-loop PI controller, which includes a current loop PI controller and a speed loop PI controller; the current loop PI controller has voltage feedforward compensation.

[0042] Optionally, the current loop PI controller has voltage feedforward compensation, specifically including: utilizing the q-axis current to perform feedforward compensation on the d-axis voltage, and utilizing the d-axis current to perform feedforward compensation on the q-axis voltage.

[0043] In a second aspect, a computer device is provided, comprising a processor and a memory; wherein, when the processor executes a computer program stored in the memory, the steps of the electric cylinder running speed control method based on trajectory planning as described in any one of the first aspects are implemented.

[0044] In a third aspect, a computer-readable storage medium is provided for storing a computer program; when the computer program is executed by a processor, the steps of the electric cylinder running speed control method based on trajectory planning as described in any one of the first aspects are implemented.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention performs trajectory planning on the running speed curve of the electric cylinder, so that when the electric cylinder is started and stopped and accelerated and decelerated, its acceleration curve is a continuous curve starting from zero without sudden changes, thereby avoiding sudden changes in the loading force of the electric cylinder caused by sudden acceleration, effectively reducing system vibration, and improving the position control accuracy of the electric cylinder.

[0047] (2) The target speed curve of the electric cylinder of the present invention solves the problem of flexible impact caused by the discontinuous acceleration curve and the sudden change in the traditional trapezoidal acceleration and deceleration algorithm and the exponential acceleration and deceleration algorithm. At the same time, the acceleration speed curve of the present invention is basically continuous, which further improves the flexibility compared with the seven-segment S-curve acceleration and deceleration algorithm. In addition, the acceleration speed curve of the present invention is constructed by a quadratic function, which is simple to calculate and easy to implement in an embedded system compared with the trigonometric function S-curve acceleration and deceleration algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a block diagram of the electric cylinder control system of the present invention;

[0049] Figure 2 It is a flow chart of the electric cylinder running speed control method based on trajectory planning of the present invention. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0051] It should be noted that the term "comprises" and any variations of the term in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or apparatus.

[0052] like Figure 1 and Figure 2 As shown, a method for controlling the running speed of an electric cylinder based on trajectory planning is provided, comprising the following steps:

[0053] Step S1: obtaining an initial speed curve of the electric cylinder, wherein the initial speed curve includes a uniform speed section, an elastic stage and a determination stage; the elastic stage includes a uniform acceleration section and a uniform deceleration section; the determination stage includes an acceleration section, a deceleration section, an acceleration and deceleration section and a deceleration and deceleration section.

[0054] Step S1 specifically includes: designing and planning the acceleration curve of the electric cylinder through a quadratic function, and obtaining an initial acceleration curve, an initial velocity curve and an initial displacement curve by continuously integrating time.

[0055] The acceleration curve of the electric cylinder is:

[0056]

[0057] Among them, τ i =tt i-1 , (i=1,2,3…7); j(t) is the acceleration at time t, a m is the expected maximum acceleration, j m is the expected maximum jerk, and t1, t2, t3, t4, t5, t6 and t7 are the running end times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively.

[0058] By integrating the jerk curve, the initial acceleration curve, initial velocity curve and initial displacement curve are further obtained.

[0059] The initial acceleration curve is:

[0060]

[0061] Where a(t) is the acceleration at time t.

[0062] The initial speed curve of the electric cylinder is:

[0063]

[0064] Where v(t) is the velocity at time t, v s is the initial speed of the electric cylinder, v1, v2, v3, v4, v5 and v6 are the speeds at the end of the acceleration section, uniform acceleration section, deceleration section, uniform speed section, acceleration and deceleration section and uniform deceleration section respectively, v m is the expected maximum operating speed of the electric cylinder.

[0065] The initial displacement curve of the electric cylinder is:

[0066]

[0067] Wherein, s(t) is the displacement at time t, S1, S2, S3, S4, S5 and S6 are the displacements at the end time of the acceleration segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment and uniform deceleration segment respectively.

[0068] The present invention adopts a cubic polynomial acceleration and deceleration algorithm to design and plan the jerk curve through a quadratic function, so that the acceleration section and the deceleration section of the jerk curve are both continuous curves, which effectively improves the flexibility.

[0069] Step S2: According to the initial working state and the expected working state of the electric cylinder, the assumed running time of each segment in the initial speed curve is obtained.

[0070] The initial working state of the electric cylinder is the initial speed v of the electric cylinder. s ; The expected working state of the electric cylinder includes the expected maximum operating speed v m , expected maximum acceleration a m 、Expected maximum jerk j m and the expected displacement value S r .

[0071] The assumed running time of each segment in the initial speed curve includes the assumed running time T1 of the acceleration segment, the assumed running time T2 of the uniform acceleration segment, the assumed running time T3 of the deceleration segment, the assumed running time T4 of the uniform speed segment, the assumed running time T5 of the acceleration / deceleration segment, the assumed running time T6 of the uniform deceleration segment and the assumed running time T7 of the deceleration / deceleration segment; T i =t i -t i-1 , (i=1,2,3…7).

[0072] According to the initial acceleration curve and the assumed running time of the jerk segment, it can be known that the assumed running time T1 of the jerk segment and the expected maximum acceleration a m and the expected maximum jerk j m The relationship is as follows:

[0073] -8j m 2 T1+4j m a m -a m =0

[0074] Simplifying, we can get

[0075] Since the acceleration process and deceleration process of the cubic polynomial acceleration and deceleration algorithm are processes with opposite acceleration, in order to ensure stability, the acceleration segment, deceleration segment, acceleration and deceleration segment and deceleration and deceleration segment are all processes with opposite acceleration values.

[0076] therefore,

[0077] In addition, according to the jerk curve, the assumed running time of the jerk section is T1, the assumed running time of the uniform acceleration section is T2, and the initial speed v of the electric cylinder is s , expected maximum acceleration a m 、Expected maximum jerk j m The relationship is as follows:

[0078]

[0079] Therefore, simplifying, we get:

[0080] The expected displacement value S of the electric cylinder during the entire acceleration and deceleration process r It consists of the displacement in the acceleration stage, the displacement in the deceleration stage and the displacement in the uniform speed stage.

[0081] The displacement value SA in the acceleration phase and the displacement value SD in the deceleration phase are:

[0082]

[0083] T a =T d =T2+2T1

[0084] Among them, T a is the displacement value and total running time of the acceleration phase, T d is the displacement value and total running time of the deceleration phase.

[0085] The displacement of the uniform speed segment can be obtained by subtracting the displacement of the acceleration segment and the displacement of the deceleration segment from the expected displacement value. The assumed running time of the uniform speed segment can be further obtained as:

[0086]

[0087] Step S3: Determine whether the elastic stage and the uniform speed stage exist respectively. If both exist, the initial speed curve is the target speed curve, and the assumed running time of each segment is the target running time of each segment; if both do not exist, the determined stage is the target speed curve, and the target running time of each segment in the determined stage is obtained according to the target speed curve; if the uniform speed segment exists and the elastic stage does not exist, the uniform speed segment and the determined stage are the target speed curve, the assumed running time of the uniform speed segment is the target running time of the uniform speed segment, and the target running time of each segment in the determined stage is obtained according to the target speed curve; if the elastic stage exists and the uniform speed segment does not exist, the elastic stage and the determined stage are the target speed curve, and the assumed running time of the elastic stage and the determined stage are the target running time of the elastic stage and the determined stage.

[0088] Specifically, it is judged whether the elastic stage and the uniform speed stage exist respectively, including judging whether the elastic stage exists and judging whether the uniform speed stage exists; since the running time of the uniform acceleration stage and the uniform deceleration stage of the elastic stage are consistent, the existence of the uniform acceleration stage and the uniform deceleration stage is also consistent, and for judging whether the uniform acceleration stage and the uniform deceleration stage exist, one judgment condition can be used for judgment.

[0089] Specifically, according to the formulas for obtaining T2 and T6 in step S2, the critical condition for the existence of the elastic stage is: Therefore, the conditions for judging whether the elastic stage exists are: If yes, then the elastic stage exists, if no, then Then the elastic phase does not exist.

[0090] Whether a uniform speed segment exists depends on whether the expected displacement value is greater than the sum of the displacement in the acceleration phase and the displacement in the deceleration phase; therefore, the condition for judging whether a uniform speed segment exists is: SA+SD<S r ; If so, the uniform speed segment exists; if not, the uniform speed segment does not exist.

[0091] Step S3 specifically includes:

[0092] When both the uniform speed segment and the elastic stage exist, the initial speed curve is the target speed curve, that is, the target speed curve includes the acceleration segment, the uniform acceleration segment, the deceleration segment, the uniform speed segment, the acceleration and deceleration segment, the uniform deceleration segment and the deceleration and deceleration segment. Then the target running time corresponding to the target speed curve is:

[0093]

[0094] When neither the uniform speed segment nor the elastic segment exists, the determination stage of the initial speed curve is the target speed curve, that is, the target speed curve only includes the acceleration segment, the deceleration segment, the acceleration and deceleration segment, and the deceleration and deceleration segment. Then the target running time of each segment corresponding to the target speed curve is:

[0095]

[0096] When the uniform speed segment exists and the elastic stage does not exist, the uniform speed segment and the determination stage of the initial speed curve are the target speed curve, that is, the target speed curve includes the acceleration segment, the deceleration segment, the uniform speed segment, the acceleration and deceleration segment, and the deceleration and deceleration segment; then the target running time of each segment corresponding to the target speed curve is:

[0097]

[0098] When the elastic stage exists and the uniform speed stage does not exist, the elastic stage and the determination stage of the initial speed curve are the target speed curve, that is, the target speed curve includes the acceleration stage, the uniform acceleration stage, the deceleration stage, the acceleration and deceleration stage, the uniform deceleration stage and the deceleration and deceleration stage. Then the target running time of each stage corresponding to the target speed curve is:

[0099]

[0100] Among them, T1, T2, T3, T4, T5, T6 and T7 are the assumed running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively; T1', T2', T3', T4', T5', T6' and T7' are the target running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively.

[0101] Step S4: Based on the target running time of each segment, the target speed curve of the electric cylinder is converted into a speed control signal of the electric cylinder driving motor to achieve the running speed control of the electric cylinder.

[0102] Step S4 specifically includes: according to the relationship between the running speed of the electric cylinder and the speed of the driving motor and the target running time of each segment in the target speed curve, converting the target speed curve into an expected input signal of the speed of the driving motor, and inputting it into the motor speed controller, so that the motor speed controller outputs a speed control signal of the driving motor.

[0103] During the entire operation process of the electric cylinder, whether it is starting or stopping, or accelerating or decelerating, its acceleration value starts from zero and gradually rises and falls along the planned acceleration curve without sudden changes, and accelerates and decelerates smoothly, rather than immediately suddenly changing to the maximum value within the allowable range for rapid acceleration and deceleration after obtaining the control signal. The system's transient response time to the control signal, especially the step signal, will be reduced; therefore, the motor speed controller of the present application adopts a dual closed-loop PI controller, which includes a current loop PI controller and a speed loop PI controller; the current loop PI controller has voltage feedforward compensation.

[0104] More specifically, the d-axis voltage is feed-forward compensated using the q-axis current, and the q-axis voltage is feed-forward compensated using the d-axis current.

[0105] The d-axis voltage is fed forward using the q-axis current, and the output voltage is calculated as follows:

[0106]

[0107] Among them, -ω e L q i q is the feedforward term;

[0108] The d-axis current is used to feed-forward compensate the q-axis voltage, and the output voltage is calculated as follows:

[0109]

[0110] Among them, -ω e L d i d +ω e ψ f is the feed-forward term.

[0111] According to the relationship between the running speed of the electric cylinder and the speed of the driving motor, the target speed curve of the electric cylinder planned by the acceleration and deceleration algorithm is converted into an expected input signal of the motor speed and input into the motor speed controller, and the signal is subtracted from the feedback value of the actual motor speed. The response speed of the motor is controlled through double closed-loop PI adjustment of the speed loop and the current loop. Since the planned speed curve of the electric cylinder as the expected input signal of the speed loop is a smoothly changing continuous curve, the transition of the motor speed between different working conditions can be smoothly switched, which effectively improves the stability of the system. At the same time, compensation is performed through feedforward control to improve the response speed of the controller and compensate for the loss of response time of the electric cylinder acceleration and deceleration algorithm in order to improve the smoothness of system operation and the control accuracy of the motor.

[0112] In another embodiment, the present invention provides a computer device, including a processor and a memory; wherein, when the processor executes a computer program stored in the memory, the steps of the above-mentioned electric cylinder running speed control method based on trajectory planning are implemented.

[0113] For more specific processes of the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be repeated here.

[0114] In another embodiment, the present invention provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the above-mentioned electric cylinder running speed control method based on trajectory planning are implemented.

[0115] For more specific processes of the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be repeated here.

[0116] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device and storage medium disclosed in the embodiment, since they correspond to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0117] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention or some parts of the embodiments.

[0118] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A method for controlling the speed of an electric cylinder based on trajectory planning, characterized in that: include: Step S1: obtaining an initial speed curve of the electric cylinder, wherein the initial speed curve includes a uniform speed section, an elastic stage and a determination stage; the elastic stage includes a uniform acceleration section and a uniform deceleration section; the determination stage includes an acceleration section, a deceleration section, an acceleration and deceleration section and a deceleration and deceleration section; Step S2: acquiring the assumed running time of each segment in the initial speed curve according to the initial working state and the expected working state of the electric cylinder; Step S3: Determine whether the elastic stage and the uniform speed stage exist respectively. If both exist, the initial speed curve is the target speed curve, and the assumed running time of each stage is the target running time of each stage; if both do not exist, the determination stage is the target speed curve, and the target running time of each stage in the determination stage is obtained according to the target speed curve; if the uniform speed stage exists but the elastic stage does not exist, the uniform speed stage and the determination stage are the target speed curve, and the assumed running time of the uniform speed stage is the target running time of the uniform speed stage, and the target running time of each stage in the determination stage is obtained according to the target speed curve; if the elastic stage exists but the uniform speed stage does not exist, the elastic stage and the determination stage are the target speed curve, and the assumed running time of the elastic stage and the determination stage is the target running time of the elastic stage and the determination stage; Step S4: Based on the target running time of each segment, the target speed curve of the electric cylinder is converted into a speed control signal of the electric cylinder driving motor to achieve the running speed control of the electric cylinder.

2. The electric cylinder running speed control method based on trajectory planning according to claim 1 is characterized in that: In the step S1, the initial velocity curve of the electric cylinder is obtained, which specifically includes: designing the acceleration curve of the electric cylinder through a quadratic function, and obtaining the initial acceleration curve, the initial velocity curve and the initial displacement curve by continuously integrating time.

3. The electric cylinder running speed control method based on trajectory planning according to claim 2 is characterized in that: The acceleration curve of the electric cylinder is: Among them, τ i =tt i-1 , (i=1,2,3…7); j(t) is the acceleration at time t, a m is the expected maximum acceleration, j m is the expected maximum jerk, t1, t2, t3, t4, t5, t6 and t7 are the running end times of the jerk section, uniform acceleration section, deceleration section, uniform speed section, acceleration and deceleration section, uniform deceleration section and deceleration and deceleration section respectively; The initial speed curve of the electric cylinder is: Where v(t) is the velocity at time t, v s is the initial speed of the electric cylinder, v1, v2, v3, v4, v5 and v6 are the speeds at the end of the acceleration section, uniform acceleration section, deceleration section, uniform speed section, acceleration and deceleration section and uniform deceleration section respectively, v m is the expected maximum operating speed of the electric cylinder.

4. The electric cylinder running speed control method based on trajectory planning according to claim 1 is characterized in that: In step S2, the initial working state of the electric cylinder is the initial speed v of the electric cylinder. s The expected working state of the electric cylinder includes the expected maximum operating speed v m , expected maximum acceleration a m 、Expected maximum jerk j m and the expected displacement value S r The assumed running time of each segment in the initial speed curve includes the assumed running time T1 of the acceleration segment, the assumed running time T2 of the uniform acceleration segment, the assumed running time T3 of the deceleration segment, the assumed running time T4 of the uniform speed segment, the assumed running time T5 of the acceleration / deceleration segment, the assumed running time T6 of the uniform deceleration segment and the assumed running time T7 of the deceleration / deceleration segment; The assumed running time of each segment in the initial speed curve is obtained by the following formula: T a =T d =T2+2T1 Among them, SA and T a are the displacement value and total running time of the acceleration phase, SD and T d are the displacement value and total running time in the deceleration phase respectively.

5. The electric cylinder running speed control method based on trajectory planning according to claim 1 is characterized in that: In step S3, the respectively determining whether the elastic stage and the uniform speed segment exist includes determining whether the elastic stage exists and determining whether the uniform speed segment exists; The condition for judging whether the elastic stage exists is: If yes, then the elastic phase exists, if no, then the elastic phase does not exist; The condition for judging whether a uniform speed segment exists is: SA+SD<S r ; If so, the uniform speed segment exists; if not, the uniform speed segment does not exist.

6. The electric cylinder running speed control method based on trajectory planning according to claim 1 is characterized in that: The step S3 specifically includes: when both the uniform speed stage and the elastic stage exist, the target running time corresponding to the target speed curve is: When neither the uniform speed segment nor the elastic stage exists, the target running time of each segment corresponding to the target speed curve is: When the uniform speed segment exists and the elastic stage does not exist, the target running time of each segment corresponding to the target speed curve is: When the elastic stage exists and the uniform speed stage does not exist, the target running time of each stage corresponding to the target speed curve is: Among them, T1, T2, T3, T4, T5, T6 and T7 are the assumed running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively; T1', T2', T3', T4', T5', T6' and T7' are the target running times of the jerk segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration / deceleration segment, uniform deceleration segment and deceleration / deceleration segment respectively.

7. The electric cylinder running speed control method based on trajectory planning according to claim 1 is characterized in that: The step S4 specifically includes: According to the relationship between the running speed of the electric cylinder and the speed of the driving motor and the target running time of each segment in the target speed curve, the target speed curve is converted into an expected input signal of the speed of the driving motor, and input into the motor speed controller so that the motor speed controller outputs a speed control signal of the driving motor; The motor speed controller adopts a double closed-loop PI controller, which includes a current loop PI controller and a speed loop PI controller; the current loop PI controller has voltage feedforward compensation.

8. The electric cylinder running speed control method based on trajectory planning according to claim 7 is characterized in that: The current loop PI controller has voltage feedforward compensation, which specifically includes: using the q-axis current to perform feedforward compensation on the d-axis voltage, and using the d-axis current to perform feedforward compensation on the q-axis voltage.

9. A computer device, characterized in that: It comprises a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the electric cylinder running speed control method based on trajectory planning as described in any one of claims 1-8 are implemented.

10. A computer-readable storage medium, characterized in that: Used to store computer programs; when the computer programs are executed by the processor, the steps of the electric cylinder running speed control method based on trajectory planning as described in any one of claims 1-8 are implemented.

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