The grow-cell belongs to a relatively new category of plant factory in the horticultural industry, for which the motivation is the maximization of production and the minimization of energy consumption. This article takes a systems design approach to identify the engineering requirements of a new grow-cell facility, with the prototype based on a 12 m X 2.4 m X 2.5 m shipping container. Research contributions are made in respect to: (i) the design of a novel conveyor-irrigation system for mechanical movement of plants; (ii) tuning of the artificial light source for plant growth; and (iii) investigations into the environmental conditions inside the grow-cell, including the temperature and humidity. In particular, the conveyor-irrigation and lighting systems are optimised in this article to make the proposed grow-cell more effective and sustainable. With regard to micro-climate, data are collected from a distributed sensor array to provide improved understanding of the heterogeneous conditions arising within the grow-cell, with a view to future optimisation. Preliminary growth trials demonstrate that Begonia semperflorens can be harvested to the satisfaction of a commercial grower. In future research, the prototype unit thus developed can be used to investigate production rates, plant quality and whole system operating costs

The design and test of a robot-compatible, radiation detection instrument providing simultaneous γ-ray imaging and γ-ray spectroscopy is described. The sensing system comprises a cerium bromide inorganic scintillation detector and a cylindrical, lead slot collimator that is configured with a robot-compatible, on-board data acquisition system. The mount for the sensor is a lightweight, bespoke 3-axis gimbal actuated by servos for pan, tilt and rotation of the collimator for imaging capability. This paper discusses the integration of this relatively low-cost radiation detection apparatus with a commercially available, Robot-Operating-System-controlled robotic platform (a Clearpath Robotics™ Jackal). The detection system is compliant with the power and mass payload constraints of the robot. Its performance has been evaluated by means of two practical examples: a) measurements in a laboratory environment to assess the ability of the system to resolve two caesium-137 point sources, and b) deployment at the Jožef Stefan Institute TRIGA Mark II research reactor to assess the ability of the system to characterise the γ-ray emission at 1 kW from a horizontal tangential beam port in the reactor hall and from the reactor sample pool above the core.

The article proposes a hypothetico-inductive approach to the formulation of suitable thermal zones, for subsequent multi-zone modelling and spatial control of microclimatic variables in buildings. Here, model structures are initially identified from data, thus avoiding undue reliance on prior hypotheses and ensuring that the resulting models are fully identifiable from the available temperature measurements. More specifically, an agglomerative hierarchical clustering approach is used to quantitatively distinguish and group thermal zones within an open airspace for any given ventilation and heating combination. To evaluate the new approach, the article utilises a previously developed Hammerstein type model for temperature, which is extended in this article to address the multi-zone modelling case. Experimental results are presented for a laboratory forced ventilation chamber, instrumented with 30 thermocouples, and recommendations are given for future application to a closed-environment agricultural grow cell being developed by the authors and industrial partners.

The research behind this article aims to reduce the operational costs and energy consumption of closed-environment growing systems, or grow-cells. Essentially a sealed building with a controlled environment, and insulated from outside lighting, grow-cells are configured to suit the particular crop being produced. The article briefly reviews the concept and preliminary work in relation to a prototype being developed by the authors and collaborating industry partner. Here, limitations in the temperature control system can lead to significant thermal gradients and poor efficiency. In this regard, the main focus of the article concerns a novel approach to thermal modelling that includes quantitative identification of spatial zones with similar thermal characteristics and the estimation of steady state temperature functions based on the heater and fan input voltages. These are combined with either a linear or a state-dependent parameter model, to represent the transient response. This approach yields a Hammerstein type model which, in this article, is optimised and evaluated using experimental data collected from 30 ther-mocouples distributed around an environmental test chamber.