Load Characteristics and Modeling Methods for the Flow Regulator of a Solid Ducted Rocket

Abstract

The load characteristics for the flow regulator of a solid ducted rocket are discussed in this paper. The mechanism and the influence factor of the load in the flow regulator were studied both theoretically and experimentally, and the system load and the working load were divided according to the mechanism. Additionally, the load influence on the working quality of the flow regulator and the ducted rocket were analyzed. System modeling of the flow regulator was carried out based on the working mechanism of the gas generator and the Stribeck friction model, and models of the actuator, gas generator, and load were built. Furthermore, considering the identification of the model parameters and the inapplicability of the conventional Stribeck identification method to the flow regulator, a new Stribeck model parameter identification method was proposed. A sine wave was used as the signal source, and specially designed devices were used to accomplish the switch of the working condition. Through the use of the genetic algorithm, the rotational inertia and parameters of the system load and working load were identified by stages. Finally, the validation of the identification method was carried out with a simulation.

Hybrid Modeling Method of SDR Interstage Valve Based on Mechanism and Data-Driven

“…However, calculating the hypothetical value of the valve according to Equation (10) would face a problem, that, when the valve changes its motion direction in the area below the "balance angle", its theoretical value will change abruptly due to the change in the action direction of the force, but this does not satisfy the laws of physics (refer to Figure 12(b)). Therefore, this paper used Equation (11) to Equation (13) to deal with this mutation. A constant value was maintained for some time when the valve changed the direction of movement, which was equivalent to the effect of the adaptive width "dead zone".…”

“…For the convenience of calculation, we can perform Taylor expansion on the trigonometric terms in Equation ( 16), and only keep the first three terms. Finally, we could obtain the estimated value of the throat area as shown in Equation (20), where b θ V could be calculated by Equation ( 10)- (13).…”

“…In this way, the approximate dynamic response range of the mechanism could be obtained, but the specific value of the clearance needs to be clarified [12]. For SDR systems, the load characteristics of the servo motor were divided into working load and system load, and the genetic algorithm was used for parameter identification [13]. However, it was not accurate to equate pneumatic load with the mechanical load.…”

Adaptive Backlash Compensation Method Based on Touch State Observation for a Solid Ducted Rocket

“…There is an assumption for this hysteresis model: when the backlash is in the hold stage CD and FA, the output of the driven part (valve) can keep constant, and its underlying cause is that there is an existing large damping or load in the driven part to keep the valve still during the hold stage. The load characteristics for the flow regulator of a solid ducted rocket are discussed in reference [19]. It is obvious that the valve has a large system load and working load to keep it still during the hold stage; in other words, the assumption for the hysteresis model stands.…”