5 results about "Singular problems" patented technology

The invention relates to a flight path tracking control method for an unmanned autonomous submersible vehicle, and belongs to the technical field of unmanned submersible vehicle control. The method comprises the following steps: firstly, establishing a nonlinear dynamic model of the submersible vehicle, analyzing kinematics and dynamic characteristics of the nonlinear dynamic model, considering various underwater forces and moments, and defining an inertial coordinate system and a submersible vehicle body coordinate system to obtain a kinematics equation and a dynamic equation so as to provide a basis for control design; secondly, a non-singular integral terminal sliding mode control method is adopted, a sliding mode surface is designed, the singular problem of traditional sliding mode control is avoided, a sliding mode control law is deduced, system finite time convergence to a balance point is achieved, and an expected state is rapidly tracked. And finally, a brand new and simple adaptive control strategy is provided, an adaptive law is designed according to system errors and sliding mode surface information, a gain matrix is adjusted in real time, and system uncertainty and external interference are compensated. The method has the advantages of being high in robustness, rapid in convergence, simple and easy to implement.

The invention relates to a multi-angle entering three-dimensional vector guidance method meeting position constraint, and belongs to the technical field of guidance. Compared with a traditional method, advanced alignment of the entry angle is achieved under the given position constraint condition, meanwhile, the space plane constraint and the constraint of the tail section attack vector direction are considered, the space vector guidance method is adopted, the minimum rotation angle and the corresponding space rotation axis can be calculated, and therefore guidance law design is completed. According to the method, the optimal rotation vector and the minimum rotation angle of the space can be calculated, the singular problem of a large-angle Euler angle universal lock in a traditional guidance method is avoided, and striking under the constraint of the terminal angle is achieved on the premise that the constraint condition of the space position plane where the entering angle is located is met. According to the method, the conditions such as the optimal space rotation axis, the minimum space rotation angle, the space plane constraint and the tail end entering vector direction constraint are considered, so that the method has universality, multiple application scenes, wide application range, excellent performance and high engineering practice ability.

The invention discloses a sound source localization method based on same-order relative circular harmonic coefficients. The method is used for solving the singular problem of an open type circular array in a Bessel zero frequency interval and a high-order low-frequency range. When a circular harmonic domain characteristic wave beam is processed, mode intensity compensation is usually adopted to eliminate dependence on array characteristics. However, the problem of singularity exists in the frequency with very small modal intensity amplitude. In combination with the same-order mode intensity consistency characteristic, a new positioning feature same-order relative circular harmonic coefficient is designed, dependence on microphone array characteristics is removed, and the influence of a singular problem on a positioning result is also solved. The positioning algorithm provided by the invention has relatively low calculation complexity, and can be efficiently deployed on a hardware platform with limited resources. On the basis of keeping low calculation complexity, the method still shows excellent positioning precision in a high-noise and high-reverberation environment.

This invention discloses a collaborative optimization design method for bearing systems based on TRIZ theory, belonging to the field of mechanical design and innovation methods. First, based on the optimization requirements of the bearing system performance, this invention establishes a three-level functional model of supersystem-system-subsystem and identifies key problem clusters. The functional model includes at least one of the following: useful functions, harmful functions, insufficient functions, and excessive functions. Then, based on the three-level functional model, contradiction solutions and resource analysis are performed at the component level, system level, and supersystem level to obtain contradiction solutions. Subsequently, a matter-field model is constructed and solved, and the TRIZ evolutionary law is applied to guide system reconstruction to obtain a system evolution scheme. Finally, the contradiction solutions and the system evolution scheme are cross-integrated and their feasibility is evaluated to generate an innovative conceptual design scheme for the bearing system. This invention effectively solves the problems of existing technologies being limited to single problems and isolated components.

The invention discloses a flexible joint space robot fixed time trajectory tracking control method and system based on instruction filtering, and the method comprises the steps: constructing a dynamic model of a three-dimensional free flight flexible joint space robot system with controlled base seat posture and mechanical arm joints; then, a fixed time disturbance observer is constructed to estimate lumped disturbance of the system, a fixed time instruction filter with a hyperbolic tangent function is combined to construct an error vector of a system state, a filtering error compensation system is designed, and then a system state error vector after filtering error compensation is constructed; and finally, a fixed time instruction filtering controller based on a hyperbolic tangent function is constructed, and fixed time trajectory tracking control of the flexible joint space robot is achieved. According to the scheme, the system state error can be converged in fixed time, buffeting in the system control law is weakened, the singular problem in the control law derivation process is avoided, the filtering error is reduced, rapid convergence of the disturbance estimation error is ensured, and the control precision and robustness of the system are improved.