How to prevent the cargo space from being overweight?


Most of the projects in the three-dimensional library are operated around automation equipment such as conveyors and stackers. Since it is equipment, it must have its ability range. For example, the planned weight of the plan is 1 ton, and the results are put up. 2 tons, it is impossible to enter the warehouse normally;
Of course, this rated range will not be so accurate, just like the rated voltage of 220V, if it occasionally comes 250V, it may not be a problem, but in the long run, it will inevitably increase the wear and tear of the equipment;
It is a pity that as a customer, even if you know the capabilities of the device, you may not be aware of it when you use it;
Often the overweight cargo is placed on the conveyor.
If the conveyor can't eat the alarm on the spot, I am afraid that when I first enter the warehouse, I will not report the alarm. When I go to the middle of the road, I will have a tray. Some devices on the machine are crushed, and the equipment is processed. Especially troublesome;
Even if the conveyor has been shut down, it is possible to go to the stacker and the overweight will cause the stacker to malfunction;
How to avoid it, it is best for the customer to "pity the cherished jade". But if you can't do it, or accidentally make a mistake, the tray will go halfway, the motor will not move, and even the mechanical device will be broken, it will be a big problem;

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The key is how to circumvent such problems from the design, the thought is:


1.Pay attention to the "sickness from the mouth" and add a detection device to the conveyor on the entrance:


It is common to use the weighing machine to check the weight. Once it exceeds 5% of the rated weight, it is not allowed to enter the warehouse. There are two ways to achieve this:
1) Electronic control of its own control, such as setting 1 ton, if it is exceeded, it is allowed to enter;
2) The upper software control, once the pallet is overweight, it is not allowed to release, even the registration is not allowed;
Personal preference is second, mainly because software control is simpler and more flexible, and the cost is lower; and some functions can be extended;
For example, the weight of the inbound warehouse is recorded in the inventory, and the load distribution of each shelf can be calculated. If a stereoscopic library is always entered as a “big chunk”, considering the uniformity of the force, the allocation algorithm will take care of both. Balance of weight;
In addition, for the fine control, even when the stacker is scheduled to operate, the weight of the goods is transferred to the stacker, so that the stacker automatically adjusts the frequency converter parameters according to the weight of the goods to get out of higher cost performance (speed and power consumption). Balanced start brake curve;


2. Make settings on the inverter corresponding to the conveyor motor of the inlet:


For example, to reduce the maximum threshold of the torque, once it is overweight, it will alarm and stop moving forward;
This parameter may be opened to the upper level through the communication protocol. For different entries, different parameters may need to be set, so that the upper position can be flexibly judged;
Or change the angle, when the inbound conveyor is running, the PLC opens the torque torque parameter of the inverter to the upper information system; the upper system draws the curve function relationship according to the relationship between the torque of different weights and the output of the motor.
In this way, each time according to the value of the torsional moment, the weight can be estimated. Once it is overweight, it is alarmed by the upper position and indicates that the current data is stopped;
This method is more economical than the weighing machine. Although the weighing machine is theoretically effective, it has its drawbacks:
1) cost; this is the most important reason;
2) Commissioning, in fact, for the cost of the weighing machine, many inspection equipment still stays in the serial port communication mode, which brings great trouble to debugging and installation;
3) Control, you can electronically read the weight to upload the upper position, or the upper one to read it yourself; but be sure to deal with the release control of the tray in the timing; do not calculate the weight of the previous tray to the current tray; avoid Zhang Guan Li Dai's situation;
Of course, the method of this inverter parameter is feasible. After all, the author is not very professional on the motor and the inverter. The author has only guessed whether there is this motor torque. Maybe it is impossible to obtain it. If this is not, then the different load. The current is different,
The current can be sampled and plotted as a function of current and weight; similar effects can be achieved;


3. Pure software estimation control


What kind of software is in the tray, how many pieces of software are known, and the weight of this thing can be known in a single way; then, when registering in the warehouse, once the calculation is overweight, the registration task is not allowed;
This will have a certain preventive effect, but the trouble is to increase the maintenance of the customer, you need to calculate the total amount of each sku, and if there is packaging, this part of the weight calculation will have errors;
There may be other means, although it can't be 100% avoided. When we implement it, we can use it in combination with several means.
If there are no protection measures, then it feels a bit like "high-risk" behavior without protection; even if the operation is normal, it will affect the life; like a bridge, it is clearly rated to take 5 tons of trucks, but many 10 tons, 20 tons Also go;
Although it will not collapse for the time being, but there is no protection for "high risk", there is a potential danger of being shot.



Reprinted from the network