# Decision-Time Learning and Planning Integrated Control for the Mild Hyperbaric Chamber
## 2 Problem Formulation  
As illustrated in Figure 2, the vehicle-mounted plateau MHBC features a structural layout where the front section of the chamber housing serves as the equipment compartment. This compartment integrates key components including air compressors, air storage tanks, pipelines, valves, gauges, and control valves, collectively enabling the system control of the MHBC. The primary control objectives of the MHBC are the internal chamber pressure and the oxygen concentration. The control pipeline configuration is illustrated in Figure 3, which includes the pressurization pipeline, depressurization pipeline, oxygen supply pipeline, and oxygen exhaust pipeline. The control system employs two oil-free sliding vane compressors, which are suitable for high-altitude plateau environments, to provide pressurization. A refrigerated air dryer is installed downstream of the compressors to cool and filter the compressed air. After passing through the air dryer, the compressed air is buffered in a storage tank and then divided into two branches: one branch is directed to the chamber for pressure regulation, and the other is fed into the oxygen concentrator to meet oxygen generation requirements. The oxygen concentrator connects to the chamber via the oxygen supply pipeline, while the oxygen exhaust pipeline vents to the atmosphere. The air compressors maintain the storage tank at a predefined pressure. Between the storage tank and the chamber, two pressurization pipelines of different diameters are used to achieve fine-resolution control during the pressurization process. Correspondingly, two depressurization pipelines equipped with differently rated control valves are provided for accurate pressure release to the atmosphere. Figure 2: Layout diagram of the MHBC. The system includes the following safety measures during operation: (1) If the pressure deviates from the target by more than 500 Pa, the system temporarily halts normal operations to correct the pressure. Should the automated correction fail within a predefined period, automatic control is disabled, prompting manual valve control by operators. This protection mechanism remains inactive during training sessions. (2) Mechanical safeguards are installed in the decompression chambers for overpressure protection. These devices automatically activate to relieve excess pressure if internal pressures exceed safety thresholds. The control of MHBC falls under the category of Stochastic Optimal Control problems, particularly under unknown parameters. A known-parameter problem assumes that the system equations, cost functions, control constraints, and stochastic disturbances follow a specific mathematical model [12]. Such models can be obtained through: explicit mathematical formulations and assumptions, Monte Carlo simulations, or other computational methods implemented via software. It is important to note that there is no fundamental difference between using explicit mathematical expressions and computational simulators to derive a system model. However, in real-world MHBC operations, due to inherent uncertainties, such as chamber leakage, it is difficult to accurately describe gas flow dynamics within the chamber using a precise mathematical model. Consequently, this problem is categorized as a non-stationary, unknown-parameter system. In such cases, achieving stochastic optimal control typically involves two approaches: the first approach ignores parameter variations in system dynamics and designs a controller that is adaptable within the range of parameter uncertainties. A widely used example is the Proportional-Integral-Derivative (PID) controller, which is designed to be robust to moderate variations in system parameters [13]. The second approach involves exploring the environment and identifying its characteristics, a process commonly referred to as System Identification in control theory. During the system identification phase, a model of the dynamic system is constructed to be utilized for performing control.