Project development of a “smart” premise system for pig keeping

The economic efficiency of intensive animal husbandry on an industrial basis depends on the rational animal keeping, which is largely determined by the availability of optimal microclimate in the premises. Whatever breed and pedigree qualities animals possess, they are unable to maintain health and display their potential hereditary productive abilities without creating the necessary microclimate conditions. In the period of 2018-2020, a survey of 11 farms in Perm Krai was carried out, where respiratory, digestive, skin diseases were found, in some cases stress was observed in animals. The cost of heating livestock premises is generally much lower than losses from murrain, reduced productivity, and feed overruns. Physical properties of the air environment are unstable factors and are subject to large fluctuations. To optimize the microclimate in livestock premises, an algorithm program for computers was developed, which will allow to create a system that provides optimal conditions for keeping and maintenance of animals and improve life safety on livestock farms. In this regard, to improve the conditions of calves and cows' keeping, a project for managing microclimate parameters on farms in the conditions of Perm Krai has been developed. Microclimate management system was developed on the basis of: the Order of the Ministry of Agriculture of the Russian Federation dated October 21, 2000 No. 621 “On approval of Veterinary rules for the maintenance of pigs for the purpose of their reproduction, cultivation and sales.” Monitoring is based on automated analysis and regulation of microclimate parameters' indicators. The software and hardware implementation were done on Omron PLC.


Introduction
Breeding pigs with a high growth rate requires maintaining comfortable microclimate parameters in pigsties [1,2]. Even though a regulated microclimate is created in the premises of pig complexes, it still does not always correspond to the optimal values. Such deviations from the recommended norms can be due to the time of year, environmental and climatic conditions, building structures, features of keeping, as well as functioning efficiency of systems ensuring optimal zoohygienic parameters [3]. Numerous studies have found that unfavorable keeping conditions are the cause of significant losses of young animals (up to 40%) and lead to a decrease in productivity (by 20 -30%), which is why there is an overconsumption of feed, a reduction in the life of animals [4,5]. The microclimate study based on the laws of mass and energy conservation is studied in the work [6], the influence of microbial and bacterial flora on the vital activity of pigs is described in the work [7]. The article [8] is devoted to simulation models' development of microclimate control. This work is devoted to the development of a microclimate control system based on the use of the Omron controller [9,10].

Equipment and devices used in studies
The methodical basis for the development of a microclimate management project in pig keeping premise is Order No. 621 dated October 21, 2020. "On approval of Veterinary rules for the maintenance of pigs for the purpose of their reproduction, cultivation and sales." The hardware components of the system are: CP1 PLC programmable logic controller (14 I/O module powered by AC source), microclimate parameters sensors, gas analyzer sensors and equipment actuators. "CX-Programmer" software was used as software tools for programming.

Requirements for physical and chemical air parameters in pig breeding premises
According to the veterinary rules for pig keeping, pig stalls are divided into: (a) pigsties for young pigs and fattening; (b) pigsties for barren dams, enceinte sows, and breeding boars; (c) pigsties for nursing sows with piglets. Indicators of the microclimate in the premise depend on the season and are characterized by physical and chemical indicators: Ttemperature, W -humidity, V -air movement speed; maximum permissible concentration of harmful gases: NH3 -ammonia and H2 S -hydrogen sulfide. The enlarged microclimate control scheme is shown in Figure 1. A description of the sensors (input signals) is given in Table 1.  Output distribution (equipment drives control) is given in Table 2.

Monitoring physical parameters of the air environment
The flowgraph of the algorithm for monitoring physical parameters of the air environment on the example of air temperature regulation is shown in Figure 1. The flowgraph contains the trigger element required to supply power to the drive during the transition process.

Chemical parameters monitoring of the air environment
Manure is formed with the vital activity of pigs, which can be a source of hydrogen sulfide and ammonia with a sharp odor. Exceeding the maximum permissible concentrations (MPC) can cause animal poisoning. To develop an alert for the presence of high harmful gases concentrations in the air, monitoring of the excess MPC time was introduced to alert personnel about an adverse situation. The validity table for gas concentration monitoring is shown in table 4.
To obtain the logical equations of gas emission monitoring, minimization was carried out and the following expressions were obtained

Ladder diagrams composing and simulation modelling
For the preparation of ladder diagrams, relay-switching logic was used. The mnemonics of the scheme is shown in Figure 3. To check the correctness of the scheme, simulation modelling (Table 5) was carried out.

Conclusions
The article analyzed the air requirements of livestock premises for pig keeping based on the Order No. 621 dated October 21, 2000 of the Ministry of Agriculture of the Russian Federation. The analysis and synthesis of logical equations for monitoring and maintenance of permissible physical and chemical parameters of the air environment was carried out.
Simulation modelling was carried out, which showed positive results of the software operation.