Multi-stage tower setting mechanism without displacement sensor and control method thereof

Abstract

This invention discloses a sensorless multi-stage tower erection mechanism and its control method. The method includes: establishing a state machine with multi-stage action interlocking and setting a virtual position counting variable; when each stage of the multi-stage telescopic boom extends, the counting variable changes along a first direction and the hydraulic drive unit switches its speed accordingly each time the interval proximity switch is triggered, until the approach switch is triggered when the boom reaches its final position and stops; when each stage of the multi-stage telescopic boom retracts, the counting variable changes along a second direction and the hydraulic drive unit switches its speed accordingly each time the interval proximity switch is triggered, until the approach switch is triggered when the boom reaches its final position and stops. This invention utilizes only inexpensive proximity switches in conjunction with dual trigger blocks and counting logic to achieve a servo-like "slow-fast-slow" S-shaped speed curve, solving the hydraulic shock problem caused by the lack of a displacement sensor, eliminating the risk of disordered multi-stage action sequence, and achieving high safety.

Description

Technical Field

[0001] This invention relates to the field of special equipment control technology, and in particular to a multi-stage tower erection mechanism without displacement sensors and its control method. Background Technology

[0002] Multi-stage telescopic towers (such as communication towers and radar erection mechanisms) are typically hydraulically driven. To ensure the smoothness of the erection and dismantling process and the accuracy of positioning, traditional techniques often use wire encoders or magnetostrictive displacement sensors to provide real-time height feedback. However, these sensors are expensive and prone to damage in harsh field conditions (such as wire breakage), resulting in high maintenance costs.

[0003] If the displacement sensor is removed and only the limit switches at both ends are used, the mechanism will experience huge hydraulic shocks at the moment of start-up and stop, and the intermediate position cannot be determined. Once the power is cut off, the system will lose position information, which can easily lead to malfunctions. In addition, the installation of multi-stage mechanisms must strictly follow the sequence (e.g., the second stage can only be installed after the first stage is locked). The lack of effective position feedback and logical interlocks can easily lead to major safety accidents such as "operation before unlocking" or "deployment before being in position". Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes a low-cost, stable, and logically safe multi-stage tower erection mechanism without displacement sensors and its control method.

[0005] In a first aspect, the present invention proposes a sensorless multi-stage tower erection mechanism, comprising a multi-stage telescopic boom, a hydraulic drive unit, and a controller. The multi-stage telescopic boom comprises at least two stages of boom bodies nested sequentially. Each stage of the boom body is equipped with a zone proximity switch, a rise-to-position proximity switch, a fall-to-position proximity switch, and a pin status detection switch. In adjacent stages of the boom body, a first trigger block and a second trigger block are sequentially fixed on the inner boom body along the telescopic direction. The zone proximity switch cooperates with the first and second trigger blocks to output a speed switching signal to the controller. The rise-to-position proximity switch and the fall-to-position proximity switch output a stop signal to the controller. The pin status detection switch outputs an unlocked or locked pin status signal to the controller. The controller is electrically connected to the hydraulic drive unit and controls the operation of the hydraulic drive unit according to the received signals.

[0006] Furthermore, the hydraulic drive unit includes an adjustable flow hydraulic valve group, which is used to control the corresponding hydraulic valve group to achieve stepped speed switching according to the controller's action command.

[0007] Secondly, the present invention provides a control method for a multi-stage tower erection mechanism as described in the first aspect, comprising: Establish a state machine with multi-level action interlocking and set a virtual position counter variable; When each stage of the multi-stage telescopic boom extends, the interval proximity switch is triggered once, causing the counter variable to change along the first direction and the hydraulic drive unit to switch the speed accordingly, until the boom reaches the position and the proximity switch is triggered to stop. When each stage of the multi-stage telescopic boom retracts, the interval proximity switch is triggered once, causing the counter variable to change along the second direction and the hydraulic drive unit to switch speed accordingly, until the boom stops when the proximity switch is triggered again after descending to the designated position.

[0008] Furthermore, when each stage of the multi-stage telescopic boom extends or retracts, the hydraulic drive unit is driven to accelerate when the interval proximity switch is triggered for the first time, and to decelerate when the interval proximity switch is triggered for the second time.

[0009] Furthermore, the first direction is an increasing direction.

[0010] Furthermore, the second direction is a decreasing direction.

[0011] Furthermore, when the multi-stage telescopic arm extends, the counting is triggered by the rising edge of the proximity switch signal; when the multi-stage telescopic arm descends, the counting is triggered by the falling edge of the proximity switch signal.

[0012] Furthermore, the state machine is provided with an interlock sequence: when the controller detects that the latch state detection switch of the (N-1)th level arm body outputs a locked state signal and the extension action of the (N-1)th level arm body is completed, the extension action of the Nth level arm body is allowed; when the controller detects that the N+1th level arm body has triggered the descent proximity switch and the retraction action of the N+1th level arm body is completed, the retraction action of the Nth level arm body is allowed; where N>1.

[0013] Furthermore, after the controller issues an action command, if no signal is detected from the interval proximity switch, the rise-to-position proximity switch, or the fall-to-position proximity switch within a preset time threshold, the hydraulic drive unit is shut down.

[0014] Furthermore, the controller writes the current level and position count variables of the moving arm into a non-volatile memory in real time, and reads and restores the control state after power-on.

[0015] This invention utilizes only inexpensive proximity switches in conjunction with dual trigger blocks and counting logic to achieve a servo-like "slow-fast-slow" S-shaped speed curve, solving the hydraulic shock problem caused by the lack of displacement sensors; through a rigorous multi-level linkage and interlocking control mechanism, it eliminates the risk of disordered multi-level action sequence and achieves high safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a sensorless multi-stage tower erection mechanism proposed in this invention; Figure 2 This is a schematic diagram showing the positional layout of the intermediate proximity switch, the first trigger block, and the second trigger block in the multi-stage telescopic arm of the present invention. Figure 3 This is a flowchart of the speed control logic for the multi-stage tower erection mechanism of the present invention during its ascent. Figure 4 This is a flowchart of the speed control logic for the descent of the multi-stage tower erection mechanism of the present invention; Figure 5 This is a state machine jump diagram for the multi-level linkage and interlocking control of the multi-level tower erection mechanism of the present invention. Detailed Implementation

[0017] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them, and the scope of protection of the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] In a specific embodiment, the present invention proposes a multi-stage tower erection mechanism without displacement sensors, including a multi-stage telescopic boom 1, a hydraulic drive unit and a controller. The multi-stage telescopic boom 1 includes at least two stages of boom bodies that are nested together in sequence. Each stage of the boom body is equipped with a section proximity switch 2, a rising position proximity switch, a falling position proximity switch and a pin status detection switch.

[0019] In this application, the multi-stage telescopic arm 1 refers to arm levels that increase sequentially from the outside to the inside, in order to... Figure 1 Taking the three-stage telescopic boom as an example, the outermost boom is the first-stage boom, the middle one is the second-stage boom, the innermost one is the third-stage boom, and so on for other booms with higher stages.

[0020] In two adjacent arm sections, the inner arm section has a second trigger block 4 and a first trigger block 3 fixed sequentially along the extension direction. Specifically, as shown... Figure 2As shown, the second trigger block 4 is located at the bottom, and the first trigger block 3 is located at the top. The interval proximity switch 2 cooperates with the second trigger block 4 and the first trigger block 3 to output a position detection signal to the controller. The rising and falling proximity switches are used to output a stop signal to the controller. The pin status detection switch is used to output an unlocked or locked pin status signal to the controller. The controller is electrically connected to the hydraulic drive unit and is used to control the hydraulic drive unit to operate according to the received signals.

[0021] Specifically, the hydraulic drive unit includes an adjustable flow hydraulic valve group, which is used to control the corresponding hydraulic valve group to achieve stepped speed switching according to the controller's action command.

[0022] In a specific embodiment, the present invention also proposes a control method for the above-mentioned multi-stage tower erection mechanism, including: Establish a state machine with multi-level action interlocking and set a virtual position counter variable (Counter). When each stage of the multi-stage telescopic boom 1 extends, the interval proximity switch 2 is triggered once, and the counter variable changes along the first direction, and the hydraulic drive unit switches the speed accordingly, until it stops when the proximity switch is triggered when the boom reaches the position. When each stage of the multi-stage telescopic boom 1 retracts, the interval proximity switch 2 is triggered once, causing the counter variable to change along the second direction and the hydraulic drive unit to switch speed accordingly, until it stops when the proximity switch is triggered again after the boom has descended to the final position.

[0023] The following uses a single-stage telescopic boom as a specific embodiment to illustrate the specific setup and retraction process based on the cooperation of the interval proximity switch 2, the second trigger block 4, and the first trigger block 3 to achieve speed control. In this embodiment, the hydraulic drive unit achieves high-speed and low-speed switching by opening / closing the hydraulic valve group.

[0024] Initially, when the control system is powered on, the controller reads the current arm stage and position count variables stored before the power failure from the non-volatile memory to restore the control state. Assume the initial state is that the arm is fully retracted, and the initial bit of the position count variable is 0 (i.e., Counter=0).

[0025] like Figure 3 As shown, the setup process is as follows: The operator issues the erection command and pulls out the pin. The controller first checks the pin status detection switch, collects the unlock status signal, and after confirming that the pin is unlocked, it controls the hydraulic drive unit to start, the hydraulic valve group is at a small opening, the mechanism is in the low-speed operating range, and the boom begins to extend.

[0026] When the boom extends to the second trigger block 4 and passes the interval proximity switch 2, the interval proximity switch 2 is triggered for the first time. The controller collects the rising edge signal of the interval proximity switch 2. After receiving the signal, the controller changes the position count variable along the first direction, for example, by incrementing it by 1, changing it from Counter=0 to Counter=1, and controls the hydraulic valve group to increase the flow rate. The mechanism enters the high-speed operating range, causing the boom to extend faster.

[0027] When the boom extends to the point where the first trigger block 3 passes the interval proximity switch 2, the interval proximity switch 2 is triggered for the second time. The controller then collects the rising edge jump signal again, changing the position count variable along the first direction, from Counter=1 to Counter=2. The controller closes the high-flow valve, switches back to a small opening, and the mechanism is in the deceleration operating range, causing the boom to extend at a deceleration rate.

[0028] When the boom extends to the point where the lifting position proximity switch is triggered, the switch outputs a stop signal and maintains this signal for a certain period (e.g., 500ms, the delay time is adjusted according to the actual gap) to confirm the position. Upon receiving the signal, the controller determines that the mechanism is in the positioning zone, controls the hydraulic drive unit to stop, completely closes the valve, and then locks the latch. The controller acquires the locking status signal and controls the hydraulic drive unit to stop. At this point, the single-stage boom erection is complete.

[0029] like Figure 4 As shown, the withdrawal process is as follows: The operator issues a retraction command and pulls out the latch. The controller detects the latch status switch, collects the unlock status signal, and after confirming that the latch is unlocked, it controls the hydraulic drive unit to start, the hydraulic valve group to be at a small opening, the mechanism to be in the low-speed operating range, and the boom to begin retracting.

[0030] When the boom retracts to the point where the first trigger block 3 passes the interval proximity switch 2, the interval proximity switch 2 is triggered for the first time (relative to the retraction direction). The controller collects the falling edge signal of the interval proximity switch 2. After receiving this signal, the controller changes the position count variable along the second direction, for example, by decrementing it by 1, changing it from Counter=2 to Counter=1, and controls the hydraulic valve group to increase the flow rate, so that the mechanism enters the high-speed operating range, causing the boom to retract more rapidly.

[0031] When the boom retracts to the point where the second trigger block 4 passes the interval proximity switch 2, the interval proximity switch 2 is triggered for the second time. The controller then collects the falling edge transition signal again and changes the position count variable along the second direction, changing it from Counter=1 to Counter=0. Simultaneously, it controls the hydraulic valve group to reduce the flow rate, causing the mechanism to enter the deceleration operating range and the boom to retract at reduced speed.

[0032] When the boom retracts to the position where the descent proximity switch is triggered, the switch outputs a stop signal and maintains this signal for a certain period (e.g., 500ms, the delay time adjusted according to the actual gap) to confirm the position. Upon receiving this signal, the controller confirms the mechanism is in the designated position range, controls the hydraulic drive unit to stop, completely closes the valve, and then locks the latch. The controller then acquires the locking status signal and controls the hydraulic drive unit to stop. At this point, the single-stage boom retraction is complete.

[0033] It should be noted that after each level of the boom is fully erected (triggered by the ascending position switch), the controller forcibly resets the Counter for that level to 2. After each level of the boom is fully retracted (triggered by the descending position switch), the controller forcibly resets the Counter for that level to 0 to eliminate accumulated errors.

[0034] Throughout the entire process described above, the controller continuously writes the current stage and position count variables of the moving arm into a non-volatile memory (such as EEPROM) to handle sudden power outages. When the system is powered on, the stored values ​​are read to reset the state and prevent position loss.

[0035] Furthermore, the first direction and the second direction mentioned in the above embodiments, which are both increasing and decreasing directions, are merely examples and can be modified according to actual needs. For instance, the first direction can also be set to decrease and the second direction to increase. Additionally, while the position count variable changes by 1 each time in the above example, other values ​​can be used in practice. For example, the position count variable can change by 4 when the proximity switch 2 is triggered for the first time, and by 3 when it is triggered for the second time, etc., and is not limited to these values.

[0036] In the above embodiments, when the multi-stage telescopic boom extends, the interval proximity switch outputs a rising edge transition signal; when the multi-stage telescopic boom descends, the interval proximity switch outputs a falling edge transition signal. This is to maintain consistent counting during the ascending and descending processes, avoiding position blind spots and duplicate counting. In practical applications, it can also be specified that the interval proximity switch outputs a falling edge transition signal when the multi-stage telescopic boom extends and a rising edge transition signal when the multi-stage telescopic boom retracts; this is not a limitation.

[0037] In the above embodiment, the controller sets the maximum running time T_{max} for each stroke as a time threshold. If, after the controller issues an action command, during the extension or retraction of the arm, if T>T_{max} and no signal is detected from the interval proximity switch 2, the rise-to-position proximity switch, or the fall-to-position proximity switch, then the system is determined to be abnormal (such as mechanical jamming, sensor failure, or hydraulic leakage). At this time, the hydraulic drive unit is shut down, and an alarm signal is output to prompt the operator to check.

[0038] Due to potential vibrations or electromagnetic interference in the working environment, the signals output by the proximity switches may contain noise. After detecting the trigger signals from proximity switch 2, the rising position proximity switch, or the falling position proximity switch, the controller does not respond immediately but instead performs a pre-set waiting period. In actual operation, there is a certain delay between signal triggering and mechanism positioning. By setting a pre-set time (e.g., 500ms, the delay time can be adjusted according to the actual difference), the actual position of the mechanism can be correlated with the signal triggering position.

[0039] For the unlock or lock status signals output by the latch status detection switch, this invention employs software delay debouncing processing. Only when the unlock or lock status signal remains stable and valid after the delay ends will the controller determine it as a valid trigger signal, thereby improving the anti-interference capability of the control system.

[0040] In a specific embodiment, the state machine has a strict interlock sequence: when the controller detects that the latch state detection switch of the (N-1)th level arm body outputs a locked state signal and the extension action of the (N-1)th level arm body is completed, the extension action of the Nth level arm body is allowed; when the controller detects that the N+1th level arm body has triggered the descent proximity switch and the retraction action of the N+1th level arm body is completed, the retraction action of the Nth level arm body is allowed; where N>1.

[0041] Specifically, such as Figure 5 As shown, this embodiment takes a three-stage telescopic arm as an example, defines the current action arm stage N, sets the status code Current_Stage (1, 2, 3), and explains the sequential interlocking logic when multiple stages are linked.

[0042] Setup sequence: When the extension of the secondary boom (N=2) is required, the control system first checks the status of the primary boom (N-1=1). Two conditions must be met simultaneously: the primary boom's pin detection switch must output a locked signal, i.e., Sensor_Stage1_Pin == LOCKED; and the primary boom's extension must be complete (the rise-to-position proximity switch has been triggered and locked), i.e., Flag_Stage1_Done == TRUE. Only after both conditions are met will the controller allow the secondary boom to extend, and the speed control process is the same as in the above embodiment.

[0043] Similarly, before extending the triple boom (N=3), the controller must detect that the secondary boom (N-1=2) has been erected and locked. Only after the triple boom is locked will the deployment mechanism (radar / antenna) of the multi-stage tower erection mechanism be deployed.

[0044] Withdrawal sequence: When the retraction of the secondary boom (N=2) is required, the controller first checks the status of the tertiary boom (N+1=3). It must detect that the tertiary boom has triggered its descent proximity switch and that its retraction action is complete, meaning it is fully retracted. Only under these conditions will the controller allow the retraction of the secondary boom to proceed.

[0045] Similarly, before executing the retraction action of the first-level arm (N=1), the controller must detect that the second-level arm (N+1=2) has been fully retracted into place.

[0046] Through the above interlocking logic, the present invention strictly guarantees the safe sequence of the multi-level tower erection and dismantling process.

[0047] This invention uses the signal edge transitions of proximity switch 2 in the monitoring section to count, dividing the travel into a starting zone, an acceleration zone, a deceleration zone, and a positioning zone, thus achieving stepped speed control. Simultaneously, a state machine is used to establish a strict interlocking sequence for multi-level actions. Through rigorous software interlocking and status code mechanisms, the risk of disordered multi-level action sequences is eliminated. The power-off position memory mechanism, utilizing a combination of a virtual counter and memory, solves the problem of open-loop systems being unable to determine whether the mechanism is in the "acceleration zone" or "deceleration zone" after a power outage. The action timeout protection mechanism improves the safety of the mechanism's operation. This invention achieves smooth acceleration and deceleration and precise positioning of multi-level towers without using displacement sensors, reducing hardware costs and improving system reliability and safety.

[0048] The term "an embodiment" or "embodiment" as used in this invention refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. In the description of this invention, it should be understood that the terms "first," "second," and "third," etc., in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0049] This specification provides method operation steps as shown in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operation steps may be included. The order of steps listed in the embodiments is merely one of many possible execution orders and does not represent the only possible execution order. In actual system or server product execution, the method can be executed in the order shown in the embodiments or drawings, or in parallel (e.g., in a parallel processor or multi-threaded processing environment), or the execution order of steps without timing constraints can be adjusted.

[0050] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A multi-stage tower erection mechanism without displacement sensors, characterized in that, The system includes a multi-stage telescopic boom, a hydraulic drive unit, and a controller. The multi-stage telescopic boom comprises at least two sequentially nested boom bodies. Each boom body is equipped with a range proximity switch, a rise-to-position proximity switch, a fall-to-position proximity switch, and a pin status detection switch. In adjacent boom bodies, a first trigger block and a second trigger block are sequentially fixed on the inner boom body along the telescopic direction. The range proximity switch cooperates with the first and second trigger blocks to output a position detection signal to the controller. The rise-to-position proximity switch and the fall-to-position proximity switch output a stop signal to the controller. The pin status detection switch outputs an unlocked or locked pin status signal to the controller. The controller is electrically connected to the hydraulic drive unit and controls the operation of the hydraulic drive unit based on the received signals.

2. The multi-stage tower erection mechanism according to claim 1, characterized in that, The hydraulic drive unit includes an adjustable flow hydraulic valve group, which is used to control the corresponding hydraulic valve group to achieve stepped speed switching according to the controller's action command.

3. A control method for a multi-stage tower erection mechanism as described in claim 1 or 2, characterized in that the method... include: Establish a state machine with multi-level action interlocking and set a virtual position counter variable; When each stage of the multi-stage telescopic boom extends, the interval proximity switch is triggered once, causing the counter variable to change along the first direction and the hydraulic drive unit to switch the speed accordingly, until the boom reaches the position and the proximity switch is triggered to stop. When each stage of the multi-stage telescopic boom retracts, the interval proximity switch is triggered once, causing the counter variable to change along the second direction and the hydraulic drive unit to switch speed accordingly, until the boom stops when the proximity switch is triggered again after descending to the designated position.

4. The control method according to claim 3, characterized in that, When each stage of the multi-stage telescopic boom extends or retracts, the hydraulic drive unit is driven to accelerate when the section proximity switch is triggered for the first time, and to decelerate when the section proximity switch is triggered for the second time.

5. The control method according to claim 3, characterized in that, The first direction is the increasing direction.

6. The control method according to claim 3, characterized in that, The second direction is the decreasing direction.

7. The control method according to claim 3, characterized in that, When the multi-stage telescopic arm extends, counting is triggered by the rising edge of the proximity switch signal; when the multi-stage telescopic arm descends, counting is triggered by the falling edge of the proximity switch signal.

8. The control method according to claim 3, characterized in that, The state machine is equipped with an interlock sequence: when the controller detects that the latch state detection switch of the (N-1)th level arm body outputs a locked state signal and the extension action of the (N-1)th level arm body is completed, the extension action of the Nth level arm body is allowed; when the controller detects that the N+1th level arm body has triggered the descent proximity switch and the retraction action of the N+1th level arm body is completed, the retraction action of the Nth level arm body is allowed; where N>1.

9. The control method according to claim 3, characterized in that, If the controller does not detect the signal output by the zone proximity switch, the rise-to-position proximity switch, or the fall-to-position proximity switch within the preset time threshold after issuing the action command, the hydraulic drive unit will be shut down.

10. The control method according to claim 3, characterized in that, The controller writes the current level and position count variables of the moving arm into a non-volatile memory in real time, and reads and restores the control state after power-on.

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