CN-121979269-A - Liquid shake control S-shaped speed planning system suitable for heavy-load loop rail shuttle car curve running

CN121979269ACN 121979269 ACN121979269 ACN 121979269ACN-121979269-A

Abstract

The invention provides a liquid shaking control S-shaped speed planning system suitable for curve running of a heavy-load loop rail shuttle, and relates to the field of electric digital data processing. The track section sensing unit is used for identifying the type of the track section in real time and sending switching signals to each unit, the S-shaped speed planning unit is used for generating seven sections of speed curves with continuous jerk, the liquid sloshing detection unit is used for outputting equivalent comprehensive wave heights, the wave height feedback control unit is used for feeding back the speed correction quantity to the S-shaped speed planning unit, the ZVD input shaping unit is used for applying convolution shaping to the speed command and updating convolution kernel parameters on line under curve working conditions, and the curve differential speed coordination unit is used for respectively outputting differential speed commands to the front shaft and the rear shaft according to curve curvature radius. The invention adopts a composite control structure combining feedforward and feedback to effectively inhibit liquid shaking in the process of driving a heavy-load liquid cargo curve.

Inventors

CHEN XINAN
YU PAI
SONG XIAOKANG
WANG WEIQIANG
HUANG QINGGUANG
WANG KAISHENG
XIAO JIADONG
CHEN LILI

Assignees

浙江中扬立库技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (8)

1. The liquid shaking control S-shaped speed planning system suitable for the curve running of the heavy-load circular rail shuttle is characterized by comprising a rail section sensing unit, an S-shaped speed planning unit, a curve differential coordination unit, a liquid shaking detection unit, a wave height feedback control unit and a ZVD input shaping unit, wherein the units are operated in a shuttle PLC controller; The rail section sensing unit is connected with the shuttle bar code scanning and positioning system, reads the absolute position of the shuttle in real time, identifies the type of the current rail section and the curvature radius of the curve, sends out a curve preparation signal to each unit when the residual distance is shortened to a curve preparation distance threshold value, and sends out a curve exit signal to each unit after entering the straight line section through the curve vertex; The S-shaped speed planning unit takes the remaining travel of the current track section, the current maximum allowable speed, the maximum acceleration and the maximum jerk as planning parameters, outputs a speed instruction in each sampling period, divides a speed curve into seven sections, has constant jerk in each section and continuous acceleration without abrupt change between adjacent sections, enters a curve mode after receiving a curve preparation signal, and executes curve self-adaptive adjustment on the planning parameters; The curve differential speed coordination unit outputs differential rotation speed instructions to the front and rear shaft frequency converters respectively according to the curve curvature radius and the current speed instructions, so that the ratio of the front and rear axis speeds is consistent with the ratio of the track lengths inside and outside the curve; The liquid shaking detection unit is used for collecting the liquid shaking state in the container in real time and outputting equivalent comprehensive wave height to the wave height feedback control unit; The wave height feedback control unit operates a PID control algorithm by taking a liquid shaking safety wave height threshold value as a set value, and outputs a speed correction amount to the S-shaped speed planning unit, and the S-shaped speed planning unit outputs a speed instruction and the speed correction amount to the ZVD input shaping unit after superposing the speed instruction and the speed correction amount; the ZVD input shaping unit applies ZVD convolution shaping processing to the received speed command sequence, the shaped speed sequence obtains an acceleration command and a deceleration command through differential operation, and the acceleration command and the deceleration command and the shaped speed sequence are input into the frequency converter control interface.
2. The liquid sloshing control S-type speed planning system for curve driving of heavy-duty loop rail shuttle according to claim 1, wherein the curve preparation distance threshold is dynamically calculated according to the current speed and the maximum allowable deceleration of the shuttle, so as to ensure that the shuttle just finishes decelerating to the curve allowable speed when reaching the curve entrance.
3. A liquid sloshing control S-type speed planning system adapted for heavy-duty loop rail shuttle curve driving according to claim 2, characterized in that the S-type speed planning unit performs three parameter adjustments in curve mode: Replacing the current allowable highest speed with the curve allowable highest speed determined according to the curve curvature radius and the liquid shaking safety constraint; The time proportion of the acceleration reduction section and the acceleration reduction section is prolonged relative to the linear working condition; And if the equivalent integrated wave height exceeds the safety threshold value during the constant speed section of the curve, further depressing the speed target value of the constant speed section, and gradually recovering to the maximum allowable speed of the curve after the wave height falls within the safety threshold value.
4. A liquid sloshing control S-type speed planning system adapted for heavy-duty loop rail shuttle curve driving as claimed in claim 3, wherein there is a trigger priority and cooperative relationship between the three parameter adjustments: the time proportion of the maximum speed replacement and the acceleration reduction period of the curve is prolonged, the curve is enabled to be effective simultaneously in the same sampling period of the curve preparation signal, and the priority is highest; The active deceleration of the constant speed section is triggered only when the shuttle vehicle enters the curve constant speed section and the equivalent comprehensive wave height exceeds a safety threshold, and the priority is lower than the first two items; The active deceleration of the constant speed section and the speed correction quantity output by the wave height feedback control unit jointly act on the current speed instruction in a superposition mode in the S-shaped speed planning unit, the superposed synthesized speed instruction is provided with a lower limit constraint, and the synthesized speed is not lower than the minimum advancing speed required by ensuring that the shuttle normally passes through a curve; When the equivalent integrated wave height falls back to the safe threshold value, the speed target value of the constant speed section gradually rises to the maximum allowable speed of the curve according to the preset recovery rate, the speed correction quantity is synchronously zeroed, and the speed target value and the speed correction quantity are withdrawn in a smooth mode.
5. The liquid sloshing control S-type speed planning system for heavy-duty loop rail shuttle car curve driving according to claim 4, wherein the PID control algorithm of the wave height feedback control unit is as follows: The proportional term enables the speed correction quantity to be in direct proportion to the wave height overrun amplitude; the differential term carries out advanced correction according to the wave height change trend, and the correction is increased in advance in the rapid wave height rising stage; The integral term eliminates the steady-state wave height deviation, and is provided with limiting constraint to prevent saturation; And when the curve exit signal arrives, the integral term executes zero clearing reset, so that the integral quantity accumulated in the curve low-speed stage is prevented from causing curve-out acceleration overshoot.
6. The liquid sloshing control S-type speed planning system for heavy-duty loop rail shuttle car curve driving according to claim 5, wherein the ZVD input shaping unit uses different convolution kernel parameters under a straight line working condition and a curve working condition; Under the linear working condition, the damping period Td and the amplitude attenuation coefficient K are set according to the longitudinal excitation frequency calibration result, and the convolution kernel is fixed; Under the curve working condition, after receiving a curve preparation signal, the ZVD input shaping unit estimates the free shaking frequency of the transverse liquid according to the size of the transverse inner cavity of the container and the depth of the current liquid level, the higher the liquid level is, the lower the natural frequency is, the wider the transverse inner cavity of the container is, the lower the natural frequency is, and the Td and the K values are updated and the convolution kernel is regenerated; and after receiving the curve exit signal, the convolution kernel is restored to the linear working condition calibration parameter.
7. The system for controlling S-shaped speed planning of liquid sloshing suitable for curve driving of heavy-duty loop rail shuttle vehicle according to claim 6, wherein the convolution kernel of the ZVD input shaping unit is switched in a smooth transition mode, each coefficient of the convolution kernel is linearly interpolated and transited from the current working condition value to the target working condition value by a preset transition step number, the transition step number is determined according to the difference between the linear working condition Td and the curve working condition Td, and the transition step number is more as the difference value is larger; The judgment condition of the switching completion is that each coefficient of the convolution kernel completes linear interpolation to reach a target working condition value, and the equivalent comprehensive wave height change rate in a plurality of continuous sampling periods is lower than a preset stability judgment threshold; And if the speed correction quantity is triggered by the shuttle due to the fact that the wave height exceeds the limit in the transition period, the ZVD input shaping unit pauses the transition process, and the transition is continuously advanced after the speed correction quantity is zeroed.
8. The liquid shaking control S-shaped speed planning system suitable for curve driving of a heavy-duty loop rail shuttle vehicle as claimed in claim 7, wherein the S-shaped speed planning unit and the ZVD input shaping unit are connected in series to form a feed-forward control channel, and excitation to the liquid level is actively restrained from two layers of speed instruction generation and shaping; The wave height feedback control unit forms a feedback control channel to compensate residual liquid shake which cannot be completely eliminated by the feed-forward channel in real time; the two cooperate to form a composite control structure combining feedforward and feedback.

Description

Liquid shake control S-shaped speed planning system suitable for heavy-load loop rail shuttle car curve running Technical Field The invention relates to the field of electric digital data processing, in particular to a liquid shaking control S-shaped speed planning system suitable for curve running of a heavy-duty circular rail shuttle. Background The heavy-load loop rail shuttle is an automatic guided vehicle with tracks arranged in a closed loop in a plane, can simultaneously operate a plurality of vehicles, and is widely applied to transportation of heavy-load liquid goods in industrial logistics storage scenes. Compared with a linear reciprocating type shuttle, the circular rail shuttle has remarkable advantages in the aspects of improving conveying capacity and storage space utilization rate, and is an important development direction of automatic storage equipment. However, heavy duty liquid cargo is commonly subject to liquid sloshing during transportation. Liquid sloshing refers to the phenomenon that liquid in a container is sloshed under the action of acceleration of a carrier, the liquid overflows or goods are unstable when the carrier is light, and the container is tipped over when the carrier is heavy, so that property loss and even personnel injury are caused. Compared with the straight running working condition, the shuttle car bears the dual functions of the longitudinal acceleration and deceleration inertial force and the transverse centrifugal force under the curve running working condition, the liquid shaking excitation direction is changed from the longitudinal direction to the longitudinal and transverse coupling direction, and the liquid shaking inhibition difficulty is obviously increased. The research of the existing liquid anti-sloshing control technology is mainly focused on the fields of aerospace, tank trucks, light packaging conveying lines and the like, and the adopted means comprise container structure optimization, wave plate installation, motion curve design and the like. However, the solutions are all aimed at specific scenes, and no systematic liquid sloshing control solution aiming at the curve driving working condition of the industrial heavy-duty circular rail shuttle is available. Aiming at the problem of high liquid sloshing wave suppression, a scheme adopting a structural anti-sloshing device exists in the prior art. As disclosed in chinese patent CN115247752a, a liquid storage tank damping control device combining collision energy consumption and anti-shake is disclosed, based on tuned mass damper principle, a circular steel plate is suspended at the upper part in the cavity of the liquid storage tank, and a mass block is added, and under the action of an earthquake, the steel plate and the mass block consume vibration energy through swinging, and meanwhile, the earthquake energy is further dissipated by using the collision, so that the liquid shake wave height is reduced, and the liquid is prevented from impacting the top cover. According to the scheme, liquid shaking inhibition is achieved by additionally arranging the mechanical structure in the container, and the large liquid storage tank fixedly installed has a certain effect under the earthquake working condition. However, the scheme has the following defects that firstly, the device depends on a mechanical structure fixed in a container to play a role, the additional mass block can obviously increase the self weight of the container and is not suitable for a heavy-load shuttle scene sensitive to the load, secondly, the device is designed aiming at the low-frequency broadband characteristic of earthquake excitation, and the liquid shaking excitation in the running of a shuttle curve is derived from a motion control command, so that the device has definite frequency characteristic and predictable time sequence rule, the excitation restraining mode from the motion control source is more effective, thirdly, the device is a passive control mode, cannot be adaptively adjusted according to the real-time running state of the shuttle, and does not have the parameter switching capability between curve working condition and straight line working condition. The existing shuttle control system generally adopts a trapezoidal speed curve to carry out motion planning, step mutation exists in acceleration, impact excitation is generated on the liquid level, the liquid shaking inhibition effect is limited, and the actual requirement of heavy-load liquid goods on liquid shaking control in the process of curve running cannot be met. Disclosure of Invention The invention aims to provide a liquid shaking control S-shaped speed planning system suitable for curve running of a heavy-load loop rail shuttle car, aiming at the defects. The invention adopts the following technical scheme: a liquid shaking control S-shaped speed planning system suitable for the curve running of a heavy-load circular rail shuttle comprises a rail section se