A control method for the telescopic boom of a straight-extending insulated boom truck

Abstract

The present invention relates to a control method for the telescopic arm of a straight-extending insulated boom truck, belonging to the field of engineering equipment. In the present invention, an insulating arm is arranged on an inner steel arm, the inner steel arm is arranged on an outer steel arm, one end of an insulating arm telescopic oil cylinder is connected to the insulating arm, the other end of the insulating arm telescopic oil cylinder is connected to the inner steel arm, one end of an inner steel arm telescopic oil cylinder is connected to the inner steel arm, the other end of the inner steel arm telescopic oil cylinder is connected to the outer steel arm, an insulating arm telescopic length detection sensor is arranged on the inner steel arm, and a pull rope of the insulating arm telescopic length detection sensor is connected to the insulating arm, an inner steel arm telescopic length detection sensor is arranged on the outer steel arm, and a pull rope of the inner steel arm telescopic length detection sensor is connected to the inner steel arm. Both the insulating arm telescopic length detection sensor and the inner steel arm telescopic length detection sensor are connected to a controller, the controller is respectively connected to a digital proportional valve group and an operation console, the operation console includes a speed control handle and an operation switch, and both the speed control handle and the operation switch are connected to the controller.

Description

Technical Field

[0001] The present invention relates to a control method for the telescopic boom of a straight-extending insulating boom truck, belonging to the field of engineering equipment. Background Art

[0002] With the rapid development of the market economy, straight-extending insulating boom trucks have been widely used in the power distribution industry. The original scheme of the straight-extending insulating boom truck adopts a three-section telescopic boom structure. The inner steel boom is pushed to telescopic by a telescopic oil cylinder, and the inner steel boom and the insulating boom are synchronously telescoped by a telescopic steel wire rope. In the process of telescoping the insulating boom, the steel boom also telescopes synchronously. When the boom truck operates close to the live body, it is easy to occur that the extended distance of the insulating boom cannot reach the effective insulating length, resulting in the failure of the overall vehicle insulation function, bringing great potential safety hazards to the operators and the vehicle.

[0003] To overcome this safety risk, there are currently two solutions: One solution is to permanently externally place a part of the insulating boom to ensure the insulation of the vehicle, but this method will cause the vehicle body to become longer and the vehicle type to become larger; Another solution is that the telescopic boom adopts a sequential telescoping scheme, that is, when extending, first fully extend the insulating boom, and then extend the inner steel boom; when retracting, first fully retract the inner steel boom, and then retract the insulating boom. However, this scheme increases the stress burden on the insulating boom, and at the same time, the frequent use of the insulating boom during use also shortens the service life of the insulating boom.

[0004] In view of this, in the patent document with the application number 201811630569.0, a sequential telescoping boom system for an aerial work vehicle is disclosed, in which the sequential telescoping mechanism includes a first-stage telescopic oil cylinder and a second-stage telescopic oil cylinder arranged side by side. The telescopic end of the first-stage cylinder rod is provided with a valve plate I, and both ends of the valve plate I are connected to the mounting seat at the tail of the basic boom through mounting shafts; the tail end cylinder wall of the second-stage cylinder barrel is provided with a mounting plate and is connected to the connecting seat at the tail of the three-section boom through the mounting plate; the telescopic end of the second-stage cylinder rod is provided with a valve plate II, and both sides of the tail end cylinder wall of the first-stage cylinder barrel are horizontally fixed with cylinder barrel shafts. The valve plate II is provided with a horizontally penetrating shaft hole, and the cylinder barrel shaft on one side of the first-stage cylinder barrel wall passes through the above shaft hole and is jointly connected to the mounting seat at the tail of the second-section boom with the cylinder barrel shaft on the other side; The control method of the present application is different from the above-mentioned prior art. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, and provide a control method for the telescopic boom of a straight-extending insulating boom truck with a reasonable structural design, which can not only ensure that the insulating boom extends first and then retracts, and after meeting the insulation function of the boom truck, the insulating boom and the inner steel boom are telescopically synchronized in proportion, thereby improving the stress burden on the insulating boom and increasing the service life of the insulating boom.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: For the control method of the telescopic boom of a straight-extending insulated boom truck, the telescopic boom of the straight-extending insulated boom truck includes an insulating boom, an inner steel boom, an outer steel boom, an insulating boom telescopic oil cylinder, and an inner steel boom telescopic oil cylinder. Its structural characteristics are as follows: The telescopic boom of the straight-extending insulated boom truck further includes an insulating boom telescopic length detection sensor and an inner steel boom telescopic length detection sensor. The insulating boom is arranged on the inner steel boom, the inner steel boom is arranged on the outer steel boom. One end of the insulating boom telescopic oil cylinder is connected to the insulating boom, and the other end is connected to the inner steel boom. One end of the inner steel boom telescopic oil cylinder is connected to the inner steel boom, and the other end is connected to the outer steel boom. The insulating boom telescopic length detection sensor is arranged on the inner steel boom, and the pull rope of the insulating boom telescopic length detection sensor is connected to the insulating boom. The inner steel boom telescopic length detection sensor is arranged on the outer steel boom, and the pull rope of the inner steel boom telescopic length detection sensor is connected to the inner steel boom. Both the insulating boom telescopic length detection sensor and the inner steel boom telescopic length detection sensor are connected to a controller. The controller is respectively connected to a digital proportional valve group and an operation console. The operation console includes a speed regulation handle and an operation switch. Both the speed regulation handle and the operation switch are connected to the controller;

[0007] The control method of the telescopic boom of the straight-extending insulated boom truck is as follows:

[0008] (A), According to the input values of the speed regulation handle and the operation switch, calculate the target speed V of the telescopic action, and calculate the theoretical speed V2S of the inner steel boom telescopic in the synchronous telescopic stage, and the theoretical speed V3S of the insulating boom telescopic in the synchronous telescopic stage;

[0009]

[0010] (B), According to the extended length L3 of the insulating boom, calculate the telescopic speed V2 of the inner steel boom and the telescopic speed V3 of the insulating boom;

[0011] (B1), When L3 < LA, in the prior extension and subsequent retraction area, at this time only the insulating boom telescopic action can be performed, and the inner steel boom does not move;

[0012]

[0013] (B2), When LA ≤ L3 < LB, in the speed switching area, at this time, according to the extended length L3 of the insulating boom, interpolate and calculate the telescopic speed V2 of the inner steel boom on the straight line segment C(LA, 0) and D(LB, V2S), and interpolate and calculate the telescopic speed V3 of the insulating boom on the straight line segment A(LA, V) and B(LB, V3S);

[0014]

[0015] (B3) When LB ≤ L3 < L3MAX, within the synchronous telescoping region, the speed of the insulating arm at this time adopts the theoretical speed V3S of the insulating arm telescoping in the synchronous telescoping stage. The speed of the inner steel arm takes the theoretical speed V2S of the inner steel arm telescoping in the synchronous telescoping stage as the reference speed, and calculates the speed compensation value through the difference detL2 between the extended length L2 of the inner steel arm and the target telescoping length L2g. Here, the incremental PID algorithm is adopted. Since the speed of the insulating arm telescoping oil cylinder is relatively slow and the requirement for the speed response of the adjustment process is not high, the algorithm is simplified by removing the differential part calculation and only performing the PI algorithm to ensure that the inner steel arm and the remaining part of the insulating arm telescoping in equal proportion synchronously. The specific scheme is as follows:

[0016] (B31) Calculate the target telescoping length L2g and the difference detL2;

[0017]

[0018] (B32) Adopt the incremental PI algorithm to calculate the compensation value detV of the inner steel arm telescoping speed;

[0019]

[0020] (B33) Calculate the final telescoping speed V2 of the inner steel arm and the telescoping speed V3 of the insulating arm. The telescoping speed V3 of the insulating arm maintains the theoretical speed V3S of the insulating arm telescoping in the synchronous telescoping stage;

[0021]

[0022] During the extension action process: when the current position of the inner steel arm lags behind the target position, the compensation value detV is positive, and the extension action of the inner steel arm accelerates at this time; when the current position of the inner steel arm is ahead of the target position, the compensation value detV is negative, and the extension action of the inner steel arm decelerates at this time;

[0023] During the retraction action process: when the current position of the inner steel arm lags behind the target position, the compensation value detV is positive, and the retraction action of the inner steel arm accelerates at this time; when the current position of the inner steel arm is ahead of the target position, the compensation value detV is negative, and the retraction action of the inner steel arm decelerates at this time;

[0024] (C) Based on the relevant structural parameters, construct the relationship functions funQ2() and funQ3() of the speed and flow requirements of the inner steel arm and the insulating arm, calculate the hydraulic flow q2 required for the telescoping action of the inner steel arm according to the telescoping speed V2 of the inner steel arm, and calculate the hydraulic flow q3 required for the telescoping action of the insulating arm according to the telescoping speed V3 of the insulating arm;

[0025]

[0026] (D) According to the relevant parameters of the digital proportional valve group, the relationship functions funQd2() and funQd3() of the flow and control data of the inner steel arm and the insulating arm are constructed to calculate the action control data q2Data and the action control data q3Data that need to be sent to the inner steel arm telescopic valve and the insulating arm telescopic valve;

[0027]

[0028] The controller sends the inner steel arm telescopic valve action control data q2Data and the insulating arm telescopic valve action control data q3Data to the corresponding digital valve through the CAN bus to realize the action control of the corresponding mechanism.

[0029] Furthermore, an insulation safety mark is provided on the insulation arm.

[0030] Furthermore, the digital proportional valve group includes an inner steel arm telescopic valve and an insulating arm telescopic valve, and both the inner steel arm telescopic valve and the insulating arm telescopic valve are connected to a controller.

[0031] Furthermore, in (B2), in the speed switching area, in order to complete the speed switching as quickly as possible, the distance between the insulating arm extension length LB when the speed switching is completed and the insulating arm extension length LA that meets the insulation safety of the insulated bucket truck is generally small. At this time, the insulating arm speed changes rapidly. If a compensation algorithm is used to calculate the inner steel arm speed, the speed fluctuation value is large, and the mechanism is prone to vibration. Therefore, only the theoretical speed calculation method is used in this area.

[0032] Furthermore, in (B32), the proportional coefficient kp used in the PI compensation algorithm can respond immediately when a deviation occurs, so that the control amount changes immediately in the direction of reducing the deviation; the integral coefficient ki used in the PI compensation algorithm can respond to the accumulated deviation during the extension or contraction of the action, and is used to eliminate the influence of the system deviation. By reasonably adjusting the proportional coefficient kp used in the PI compensation algorithm and the integral coefficient ki used in the PI compensation algorithm, a reasonable compensation value detV can be calculated.

[0033] Furthermore, in (B33), by compensating the extension and retraction speed of the inner steel arm, the difference DetL2 can be ensured to be within ±15mm, which fully meets the torque control or amplitude control requirements of the original aerial work vehicle.

[0034] Furthermore, the insulating arm telescopic length detection sensor and the inner steel arm telescopic length detection sensor are both pull-rope type sensors.

[0035] Compared with the prior art, the present invention has the following advantages: During the telescoping process of the arm mechanism (insulating arm, inner steel arm, and outer steel arm), a control strategy is implemented where the insulating arm extends first and then retracts. That is, when the arm mechanism extends, the inner steel arm remains stationary first, and the insulating arm extends to a length that meets the insulation safety requirements. Then, the remaining parts of the inner steel arm and the insulating arm extend synchronously in proportion. During the retracting action of the arm mechanism, the remaining parts of the inner steel arm and the insulating arm retract synchronously in proportion first. When the inner steel arm is fully retracted, the insulating arm still leaves a length that meets the insulation safety requirements, and finally, the insulating arm is fully retracted to ensure the insulation safety during the operation of the insulated boom truck.

[0036] A telescopic arm structure is adopted in which the inner steel arm and the insulating arm can be telescoped independently. At the same time, an inner steel arm telescopic length detection sensor and an insulating arm telescopic length detection sensor are installed, which can respectively detect the telescopic positions of the inner steel arm and the insulating arm.

[0037] A digital proportional valve group with spool position feedback is used as the actuator for controlling the speeds of the insulating arm telescopic cylinder and the inner steel arm telescopic cylinder, reducing the hysteresis effect in the flow control curve and avoiding large fluctuations during the speed compensation process of the inner steel arm, which may cause the mechanism to vibrate.

[0038] There is a speed switching area to ensure that when switching between the independent telescoping and synchronous telescoping of the insulating arm, the speeds of the inner steel arm and the insulating arm are stable and there is no impact feeling.

[0039] In the synchronous telescoping area, the speed of the inner steel arm is adjusted according to the difference between the current position and the theoretical position of the inner steel arm through a speed compensation algorithm with PI regulation, ensuring that the inner steel arm and the insulating arm telescope synchronously in proportion. During the operation, the deviation between the actual position and the theoretical position of the inner steel arm is less than ±15 mm, thus ensuring the accuracy of the original torque control system of the insulated boom truck. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural diagram of the telescopic arm of the straight-extending insulated boom truck according to an embodiment of the present invention.

[0041] Figure 2 is a schematic diagram of the control principle according to an embodiment of the present invention.

[0042] Figure 3 is a schematic diagram of the action speed control according to an embodiment of the present invention.

[0043] Figure 4 is a control flowchart according to an embodiment of the present invention.

[0044] In the figure: insulating arm 1, insulating safety mark 2, inner steel arm 3, outer steel arm 4, insulating arm telescopic oil cylinder 5, insulating arm telescopic length detection sensor 6, inner steel arm telescopic length detection sensor 7, inner steel arm telescopic oil cylinder 8, controller 9, speed control handle 10, operation switch 11, digital proportional valve group 12, operation console 13, inner steel arm telescopic valve 14, insulating arm telescopic valve 15 Specific embodiments

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, and the present invention is not limited to the following embodiments.

[0046] Embodiment

[0047] See Figures 1 to 4 As shown, it should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, if terms such as "upper", "lower", "left", "right", "middle" and "one" are cited in this specification, they are only for the convenience of clear description and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.

[0048] In the control method of the telescopic arm of the straight-extending type insulating boom truck in this embodiment, the telescopic arm of the straight-extending type insulating boom truck includes an insulating arm 1, an inner steel arm 3, an outer steel arm 4, an insulating arm telescopic oil cylinder 5, an insulating arm telescopic length detection sensor 6, an inner steel arm telescopic length detection sensor 7 and an inner steel arm telescopic oil cylinder 8. The insulating arm 1 is arranged on the inner steel arm 3, the inner steel arm 3 is arranged on the outer steel arm 4, and an insulating safety mark 2 is arranged on the insulating arm 1.

[0049] One end of the insulating arm telescopic oil cylinder 5 in this embodiment is connected to the insulating arm 1, and the other end of the insulating arm telescopic oil cylinder 5 is connected to the inner steel arm 3, so that the insulating arm 1 and the inner steel arm 3 move relative to each other. One end of the inner steel arm telescopic oil cylinder 8 is connected to the inner steel arm 3, and the other end of the inner steel arm telescopic oil cylinder 8 is connected to the outer steel arm 4, so that the inner steel arm 3 and the outer steel arm 4 move relative to each other. The insulating arm telescopic length detection sensor 6 is arranged on the inner steel arm 3, and the rope end of the insulating arm telescopic length detection sensor 6 is connected to the tail of the insulating arm 1, and is used for detecting the extended length L3 of the insulating arm. The inner steel arm telescopic length detection sensor 7 is arranged on the outer steel arm 4, and the rope end of the inner steel arm telescopic length detection sensor 7 is connected to the tail of the inner steel arm 3, and is used for detecting the extended length L2 of the inner steel arm.

[0050] The insulating arm telescopic length detection sensor 6 and the inner steel arm telescopic length detection sensor 7 (both are prior arts) in this embodiment are both rope-drawing type sensors. When the drawn length of the rope of the rope-drawing type sensor changes, the internal potentiometer outputs different voltage signals, and the voltage signal is in a proportional relationship with the drawn length of the rope.

[0051] The insulating arm telescopic length detection sensor 6 and the inner steel arm telescopic length detection sensor 7 in this embodiment are both connected to the controller 9. Usually, the inner steel arm telescopic length detection sensor 7 is electrically connected to the controller 9, and the controller 9 can detect the extended length L2 of the inner steel arm according to the output voltage of the inner steel arm telescopic length detection sensor 7; the insulating arm telescopic length detection sensor 6 is electrically connected to the controller 9, and the controller 9 can detect the extended length L3 of the insulating arm according to the output voltage of the insulating arm telescopic length detection sensor 6.

[0052] The controller 9 (prior art) in this embodiment is respectively connected to the digital proportional valve group 12 and the operation console 13. The operation console 13 includes a speed regulation handle 10 and an operation switch 11. The speed regulation handle 10 and the operation switch 11 are both connected to the controller 9. Usually, the operation switch 11 is electrically connected to the controller 9, and the controller 9 can detect the operation actions of extension and retraction; the speed regulation handle 10 is electrically connected to the controller 9, and the turning angle of the speed regulation handle 10 is in a proportional relationship with the output voltage, and the controller 9 can calculate the action speed according to the output voltage of the handle.

[0053] The digital proportional valve group 12 in this embodiment includes an inner steel arm telescopic valve 14 and an insulating arm telescopic valve 15. Both the inner steel arm telescopic valve 14 and the insulating arm telescopic valve 15 are connected to the controller 9. Under normal circumstances, the components that control the movement of the insulating arm telescopic cylinder 5 and the inner steel arm telescopic cylinder 8 are the insulating arm telescopic valve 15 and the inner steel arm telescopic valve 14 respectively. The digital proportional valve group 12 is formed by integrating an advanced microprocessor, sensors, and drive circuits into an independent electronic control unit, which is directly connected to the proportional valve body. In the electronic control unit, the target position signal of the main spool is received through the CAN bus, and at the same time, the actual position signal of the spool feedback by the main spool position sensor LVDT (Linear Variable Differential Transformer). The microprocessor controls the movement of the main spool by comparing the deviation between the feedback position signal and the input target position signal to accurately reach the target position. The digital proportional valve group 12 can compensate for various influences brought by spool pressure, internal leakage, oil viscosity change, pilot pressure, etc., basically overcoming the hysteresis of the proportional valve and ensuring that the flow output curve of the proportional valve is close to the ideal linearity. Applying the digital proportional valve group 12 makes the speeds of the inner steel arm 3 and the insulating arm 1 stable and the precision high during synchronous telescopic control.

[0054] The control method for the telescopic arm of the straight-extending insulating boom truck in this embodiment is as follows:

[0055] (A), According to the input values of the speed control handle and the operation switch, calculate the target speed V of the telescopic action, and calculate the theoretical speed V2S of the inner steel arm telescopic in the synchronous telescopic stage, and the theoretical speed V3S of the insulating arm telescopic in the synchronous telescopic stage.

[0056]

[0057] (B), According to the extended length L3 of the insulating arm, calculate the telescopic speed V2 of the inner steel arm and the telescopic speed V3 of the insulating arm.

[0058] (B1), When L3 < LA, in the pre-extension and post-retraction area, at this time, only the telescopic action of the insulating arm 1 can be performed, and the inner steel arm 3 does not move.

[0059]

[0060]

[0061]

[0062] ​In the speed switching area, in order to complete the speed switching as soon as possible, the distance between the extended length LB of the insulating arm when the speed switching is completed and the extended length LA of the insulating arm that meets the insulation safety of the insulating boom truck is generally small. At this time, the speed of the insulating arm changes rapidly. If the compensation algorithm is used to calculate the speed of the inner steel arm, the speed fluctuation value is large, and the mechanism tremor is likely to occur. Therefore, only the theoretical speed calculation method is used in this area.

[0063] (B3). When LB ≤ L3 < L3MAX, in the synchronous telescopic area, at this time, the speed of the insulating arm 1 adopts the theoretical speed V3S of the insulating arm telescopic in the synchronous telescopic stage. The speed of the inner steel arm 3 takes the theoretical speed V2S of the inner steel arm telescopic in the synchronous telescopic stage as the reference speed, and calculates the speed compensation value through the difference detL2 between the extended length L2 of the inner steel arm and the target telescopic length L2g. Here, the incremental PID algorithm is adopted. Since the speed of the insulating arm telescopic oil cylinder 5 is slow and the speed response requirement for the adjustment process is not high, the algorithm is simplified, the differential part calculation is removed, and only the PI algorithm is performed to ensure that the inner steel arm 3 and the remaining part of the insulating arm 1 are proportionally synchronously telescoped. The specific scheme is as follows:

[0064] (B31). Calculate the target telescopic length L2g and the difference detL2.

[0065]

[0066] (B32). Adopt the incremental PI algorithm to calculate the compensation value detV of the inner steel arm telescopic speed.

[0067]

[0068] The proportional coefficient kp used in the PI compensation algorithm can react immediately when the deviation occurs, so that the control quantity changes immediately in the direction of reducing the deviation; the integral coefficient ki used in the PI compensation algorithm can react to the accumulated deviation during the stretching or retracting process of the action, and is used to eliminate the influence of the system deviation. Reasonably adjusting the proportional coefficient kp used in the PI compensation algorithm and the integral coefficient ki used in the PI compensation algorithm can calculate a reasonable compensation value detV.

[0069] (B33). Calculate the final telescopic speed V2 of the inner steel arm and the telescopic speed V3 of the insulating arm. The telescopic speed V3 of the insulating arm maintains the theoretical speed V3S of the insulating arm telescopic in the synchronous telescopic stage.

[0070]

[0071] During the stretching action process: when the current position of the inner steel arm 3 lags behind the target position, the compensation value detV is positive, and at this time, the stretching action of the inner steel arm 3 accelerates; when the current position of the inner steel arm 3 is ahead of the target position, the compensation value detV is negative, and at this time, the stretching action of the inner steel arm 3 decelerates.

[0072] During the retraction operation process: when the current position of the inner steel arm 3 lags behind the target position, the compensation value detV is positive, and at this time, the retraction of the inner steel arm 3 accelerates; when the current position of the inner steel arm 3 is ahead of the target position, the compensation value detV is negative, and at this time, the retraction of the inner steel arm 3 decelerates.

[0073] By compensating the telescopic speed of the inner steel arm 3, it can ensure that the difference DetL2 is within ±15 mm, fully meeting the torque control or amplitude control requirements of the original aerial work platform.

[0074] (C), Based on relevant structural parameters, construct the relationship functions funQ2() and funQ3() of the speed and flow requirements of the inner steel arm 3 and the insulating arm 1. Calculate the hydraulic flow q2 required for the telescopic movement of the inner steel arm according to the telescopic speed V2 of the inner steel arm, and calculate the hydraulic flow q3 required for the telescopic movement of the insulating arm according to the telescopic speed V3 of the insulating arm.

[0075]

[0076] (D), Based on the relevant parameters of the digital proportional valve group 12, construct the relationship functions funQd2() and funQd3() of the flow and control data of the inner steel arm 3 and the insulating arm 1, and calculate the control data q2Data for the telescopic valve of the inner steel arm and the control data q3Data for the telescopic valve of the insulating arm that need to be sent.

[0077]

[0078] The controller 9 sends the control data q2Data for the telescopic valve of the inner steel arm and the control data q3Data for the telescopic valve of the insulating arm to the corresponding digital valves through the CAN bus to realize the motion control of the corresponding mechanisms.

[0079] Specifically, a telescopic arm structure is adopted in which the inner steel arm 3 is independently controlled for telescoping through the inner steel arm telescopic oil cylinder 8, and the insulating arm 1 is independently controlled for telescoping through the insulating arm telescopic oil cylinder 5. At the same time, an inner steel arm telescopic length detection sensor 7 and an insulating arm telescopic length detection sensor 6 are installed, which can respectively detect the telescopic positions of the inner steel arm 3 and the insulating arm 1.

[0080] During the operation of the telescopic boom mechanism (insulating boom 1, inner steel boom 3, outer steel boom 4), a control strategy is implemented to extend and then retract the insulating boom 1 first. That is, when the boom mechanism extends, the inner steel boom 3 remains stationary first, and the insulating boom 1 extends to a length that meets the insulation safety requirements. Then, the remaining parts of the inner steel boom 3 and the insulating boom 1 extend synchronously in proportion. During the retraction of the boom mechanism, the remaining parts of the inner steel boom 3 and the insulating boom 1 retract synchronously in proportion first. After the inner steel boom 3 is fully retracted, the insulating boom 1 still leaves a length that meets the insulation safety requirements, and finally the insulating boom 1 is fully retracted, thus ensuring the insulation safety during the operation of the insulated aerial work platform.

[0081] After reaching the insulation safety length, enter the speed switching area to ensure that when switching between the independent telescoping and synchronous telescoping of the insulating boom 1, the speeds of the inner steel boom 3 and the insulating boom 1 transition smoothly without impact.

[0082] In the synchronous telescoping area, to keep the overall telescoping speed of the working boom unchanged, the value of the telescoping speed V3 of the insulating boom is reduced according to the theoretical ratio, and the telescoping speed V2 of the inner steel boom is executed based on the theoretical ratio as the reference speed.

[0083] According to the specific data such as the extended length L2 of the inner steel boom, the extended length L3 of the insulating boom, and the extended length LA of the insulating boom that meets the insulation safety of the insulated aerial work platform in a specific vehicle model, calculate the theoretical telescoping position of the inner steel boom 3 during equal - proportion synchronous telescoping. The compensation value detV is calculated through the difference between the current position and the theoretical position of the inner steel boom 3 by PI feedback control, and through continuous adjustment of the telescoping speed V2 of the inner steel boom, ensure the equal - proportion synchronous telescoping of the inner steel boom 3 and the insulating boom 1. In the synchronous telescoping area of the inner steel boom 3 and the insulating boom 1, at any operating speed, the deviation between the actual position and the theoretical position of the inner steel boom 3 is less than ±15mm, thus ensuring the accuracy of the original torque control system of the insulated aerial work platform.

[0084] To improve the accuracy of speed control, a digital proportional valve group 12 with spool position feedback is used as the speed control element for the telescoping cylinders 8 of the inner steel boom and the telescoping cylinders 5 of the insulating boom. The hysteresis in the flow control curve is reduced from 15% to 1%, effectively avoiding large fluctuations during the compensation of the telescoping speed V2 of the inner steel boom, which may cause mechanism vibration.

[0085] For ease of description, the following names are defined:

[0086] Among them, V: Calculate the target speed of the telescoping action according to the input values of the speed control handle and the operation switch.

[0087] Among them, V2: Telescoping speed of the inner steel boom.

[0088] Among them, V3: Telescoping speed of the insulating boom.

[0089] Among them, V2S: Theoretical telescoping speed of the inner steel boom during synchronous telescoping.

[0090] Among them, V3S: The theoretical speed of the insulating arm telescoping in the synchronous telescoping stage.

[0091] Among them, L2: The extended length of the inner steel arm.

[0092] Among them, L3: The extended length of the insulating arm.

[0093] Among them, LA: The extended length of the insulating arm that meets the insulation safety of the insulated boom truck.

[0094] Among them, LB: The extended length of the insulating arm when the speed switching is completed.

[0095] Among them, L2MAX: The extended length when the inner steel arm is fully extended.

[0096] Among them, L3MAX: The extended length when the insulating arm is fully extended.

[0097] Among them, K3: The theoretical speed coefficient of the insulating arm during synchronous telescoping calculated according to the mechanism parameters.

[0098] Among them, L2g: The target telescoping length of the inner steel arm calculated according to the insulating arm length L3.

[0099] Among them, detL2: The difference between the extended length L2 of the inner steel arm and the target telescoping length L2g.

[0100] Among them, sumDetL2: The cumulative value of the deviation detL2 of the telescoping length of the inner steel arm in a single extension or retraction action.

[0101] Among them, kp: The proportional coefficient used in the PI compensation algorithm.

[0102] Among them, ki: The integral coefficient used in the PI compensation algorithm.

[0103] Among them, detV: The compensation value of the telescoping speed V2 of the inner steel arm calculated by the PI algorithm.

[0104] Among them, q2: The hydraulic flow required for the telescoping action of the inner steel arm.

[0105] Among them, q3: The hydraulic flow required for the telescoping action of the insulating arm.

[0106] Among them, q2Data: The action control data of the inner steel arm telescoping valve.

[0107] Among them, q3Data: The action control data of the insulating arm telescoping valve.

[0108] In addition, it should be noted that for the specific embodiments described in this specification, the shapes and names of the components can be different. The above content described in this specification is only an example of the structure of the present invention. Any equivalent changes or simple changes made according to the structure, features, and principles conceived in the present invention are included in the protection scope of the present invention. Those skilled in the technical field to which the present invention pertains can make various modifications, supplements, or use similar methods for substitution to the specific embodiments described, as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A control method for the telescopic boom of a straight-extending type insulating boom truck. The telescopic boom of the straight-extending type insulating boom truck comprises an insulating boom (1), an inner steel boom (3), an outer steel boom (4), an insulating boom telescopic oil cylinder (5) and an inner steel boom telescopic oil cylinder (8), characterized in that: The telescopic boom of the straight-extending type insulated aerial work platform further includes an insulating boom telescopic length detection sensor (6) and an inner steel boom telescopic length detection sensor (7). The insulating boom (1) is arranged on the inner steel boom (3), the inner steel boom (3) is arranged on the outer steel boom (4), one end of the insulating boom telescopic oil cylinder (5) is connected to the insulating boom (1), the other end of the insulating boom telescopic oil cylinder (5) is connected to the inner steel boom (3), one end of the inner steel boom telescopic oil cylinder (8) is connected to the inner steel boom (3), the other end of the inner steel boom telescopic oil cylinder (8) is connected to the outer steel boom (4), the insulating boom telescopic length detection sensor (6) is arranged on the inner steel boom (3), and the cable of the insulating boom telescopic length detection sensor (6) is connected to the insulating boom (1). The inner steel boom telescopic length detection sensor (7) is arranged on the outer steel boom (4), and the cable of the inner steel boom telescopic length detection sensor (7) is connected to the inner steel boom (3). Both the insulating boom telescopic length detection sensor (6) and the inner steel boom telescopic length detection sensor (7) are connected to the controller (9), the controller (9) is respectively connected to the digital proportional valve group (12) and the operation console (13), the operation console (13) includes a speed regulation handle (10) and an operation switch (11), and both the speed regulation handle (10) and the operation switch (11) are connected to the controller (9); The control method of the telescopic boom of the straight-extending type insulated aerial work platform is as follows: (A) According to the input values of the speed regulation handle and the operation switch, and the theoretical speed coefficient K3, calculate the target speed V of the telescopic action, and calculate the theoretical speed V2S of the inner steel boom telescopic in the synchronous telescopic stage and the theoretical speed V3S of the insulating boom telescopic in the synchronous telescopic stage; (B) According to the extending length L3 of the insulating boom, calculate the telescopic speed V2 of the inner steel boom and the telescopic speed V3 of the insulating boom; (B1) When L3 < LA, the extending length LA of the insulating boom of the insulated aerial work platform, in the pre-extending and post-retracting area, at this time, only the telescopic action of the insulating boom (1) can be performed, and the inner steel boom (3) does not move; (B2) When LA ≤ L3 < LB, when the speed switching is completed, the extending length LB of the insulating boom, in the speed switching area, at this time, interpolate and calculate the telescopic speed V2 of the inner steel boom on the straight line segment C(LA, 0) and D(LB, V2S) according to the extending length L3 of the insulating boom, and interpolate and calculate the telescopic speed V3 of the insulating boom on the straight line segment A(LA, V) and B(LB, V3S); (B3) When LB ≤ L3 < L3MAX, the extended length L2MAX when the inner steel arm is fully extended and the extended length L3MAX when the insulating arm is fully extended. In the synchronous telescoping area, at this time, the speed of the insulating arm (1) adopts the theoretical speed V3S of the insulating arm telescoping in the synchronous telescoping stage. The speed of the inner steel arm (3) takes the theoretical speed V2S of the inner steel arm telescoping in the synchronous telescoping stage as the reference speed. Through the difference detL2 between the extended length L2 of the inner steel arm and the target telescoping length L2g, the speed compensation value is calculated. Here, the incremental PID algorithm is adopted. Since the speed of the insulating arm telescoping oil cylinder (5) is relatively slow and the speed response requirement for the adjustment process is not high, the algorithm is simplified by removing the differential part calculation and only performing the PI algorithm to ensure that the remaining parts of the inner steel arm (3) and the insulating arm (1) are telescoped synchronously in proportion. The specific scheme is as follows: (B31) Calculate the target telescoping length L2g and the difference detL2; (B32) In the PI compensation algorithm, the proportional coefficient kp and the integral coefficient ki in the PI compensation algorithm. Adopt the incremental PI algorithm to calculate the compensation value detV of the inner steel arm telescoping speed V2; (B33) Calculate the final inner steel arm telescoping speed V2 and the insulating arm telescoping speed V3. The insulating arm telescoping speed V3 maintains the theoretical speed V3S of the insulating arm telescoping in the synchronous telescoping stage; During the extension operation process: when the current position of the inner steel arm (3) lags behind the target position, the compensation value detV is positive, and at this time, the extension operation of the inner steel arm (3) accelerates; when the current position of the inner steel arm (3) is ahead of the target position, the compensation value detV is negative, and at this time, the extension operation of the inner steel arm (3) decelerates; During the retraction operation process: when the current position of the inner steel arm (3) lags behind the target position, the compensation value detV is positive, and at this time, the retraction operation of the inner steel arm (3) accelerates; when the current position of the inner steel arm (3) is ahead of the target position, the compensation value detV is negative, and at this time, the retraction operation of the inner steel arm (3) decelerates; (C) According to the relevant structural parameters, construct the relationship functions funQ2() and funQ3() of the speed and flow requirements of the inner steel arm (3) and the insulating arm (1). Calculate the hydraulic flow q2 required for the inner steel arm telescoping action according to the inner steel arm telescoping speed V2, and calculate the hydraulic flow q3 required for the insulating arm telescoping action according to the insulating arm telescoping speed V3; (D) According to the relevant parameters of the digital proportional valve group (12), construct the relationship functions funQd2() and funQd3() of the flow and control data of the inner steel arm (3) and the insulating arm (1). Calculate the control data q2Data for the inner steel arm telescoping valve action and the control data q3Data for the insulating arm telescoping valve action to be sent; The controller (9) sends the control data q2Data for the inner steel arm telescoping valve action and the control data q3Data for the insulating arm telescoping valve action to the corresponding digital valves through the CAN bus to realize the action control of the corresponding mechanisms.

2. The control method of the telescopic boom of the straight-extending type insulated boom truck according to claim 1, characterized in that: An insulating safety mark (2) is provided on the insulating arm (1).

3. The control method of the telescopic boom of the straight-extending type insulated boom truck according to claim 1, characterized in that: The digital proportional valve group (12) includes an inner steel arm telescopic valve (14) and an insulating arm telescopic valve (15), and both the inner steel arm telescopic valve (14) and the insulating arm telescopic valve (15) are connected to the controller (9).

4. The control method of the telescopic boom of the straight telescopic insulated bucket truck according to claim 1, characterized in that: In the (B2), in the speed switching area, in order to complete the speed switching as soon as possible, the distance between the extended length LB of the insulating arm when the speed switching is completed and the extended length LA of the insulating arm that meets the insulation safety of the insulating boom truck is generally small. At this time, the speed of the insulating arm changes rapidly. If the compensation algorithm is used to calculate the speed of the inner steel arm, the speed fluctuation value is large and the mechanism tremor is likely to occur. Therefore, only the method of theoretical speed calculation is used in this area.

5. The control method for the telescopic boom of a straight-extending insulated boom truck according to claim 1, characterized in that: In the (B32), the proportional coefficient kp used in the PI compensation algorithm can react immediately when the deviation occurs, so that the control quantity changes immediately in the direction of reducing the deviation; the integral coefficient ki used in the PI compensation algorithm can react to the accumulated deviation during the extension or contraction process of the action, and is used to eliminate the influence of the system deviation. By reasonably adjusting the proportional coefficient kp used in the PI compensation algorithm and the integral coefficient ki used in the PI compensation algorithm, a reasonable compensation value detV can be calculated.

6. The control method for the telescopic boom of the straight-extending type insulated boom truck according to claim 1, wherein: In the (B33), by compensating the telescopic speed of the inner steel arm (3), it can be ensured that the difference DetL2 is within ±15 mm, fully meeting the torque control or amplitude control requirements of the original aerial work platform.

7. The control method of the telescopic boom of the straight-extending insulated boom truck according to claim 1, characterized in that: Both the insulating arm telescopic length detection sensor (6) and the inner steel arm telescopic length detection sensor (7) are rope-drawing sensors.

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