The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
For low hitting precision, bad robustness and high normal acceleration of traditional torpedo guidance law, the paper designed anti-torpedo torpedo(ATT) guidance law based on variable structure control. State equation of line of sight angle between ATT and target can be achieved from mathematical model of moving relation between ATT and target torpedo, and designed a variable structure controller...
During social interaction between humans and robots, body language can contribute to communicate mutual emotional states. In this paper, a method is presented, that enables wheeled robots with differential drive to express various emotional states by means of different movement styles during goal-directed motion. The motion control of the robot utilizes an objective-based motion planner optimizing...
No restrictions are imposed on the motion states of missile and target and the line of sight rotation coordinate system is introduced into the derivation of differential geometric guidance law. Then, the extended differential geometric guidance law is achieved whose scope of application is largely extended. In order to realize the derived law, instead of the complex computation of torsion command,...
This paper proposes a general framework to establish the dynamic movement primitives library (DMPL) for a mobile robot path planning in unknown environment. Based on DMPL, the mobile robot can autonomously compute a smooth path from the initial position to the target points while avoiding any existed obstacles. Path planning based on DMPL consists of two phases, the library building and its application...
The control problem of underactuated spacecraft chaotic attitude motion is investigated based on exponential reaching law in this paper. First, the underactuated spacecraft chaotic attitude system is written in nonlinear equation form with two controls. Once the trajectory planning of angular acceleration is preset, the dynamics equation of angular velocity error can be obtained. Then, the sliding...
There are usually large uncertainties in the aerodynamic parameters of Mars entry vehicles, which inevitably degrades the performance of entry guidance algorithms. The paper presents a backstepping sliding mode controller for drag tracking in Mars entry guidance, which can guarantee the tracking error with finite-time convergence. First, the drag can track the reference trajectory under the virtual...
Entry guidance of a high-lifting vehicle is a complex problem that has attracted the attention of researchers around the world for many years. This paper classifies the previous studies into two categories: trajectory planning-tracking method (TPTM) and predictor-corrector method (PCM). A new trajectory planning method based on the dynamic pressure profile of the vehicle is proposed in this paper...
To obtain a better performance of trajectory tracking for hypersonic glide vehicles (HGVs), this paper focuses on enhancing the accuracy of tracking model, an effective method with a modified tracking model is proposed. Firstly, according to the skip glide trajectory of HTV-2, a simplified trajectory model is established to describe the periodical characteristic of the trajectory. Secondly, a modified...
This paper focuses on the minimum-time trajectory planning for a platoon of autonomous vehicles with rear-end collision avoidance along a given path under velocity and acceleration constraints. Specifically, with the aid of time-optimal path-constrained trajectory planning (TOPCTP) techniques, we present a trajectory planning algorithm to generate time-optimal velocity profiles, which guarantees the...
In this paper, we investigate identification methods for dynamic parameters of robot manipulator. The focused method is based on heuristic particle swarm optimization algorithm (PSO) with some extended features. The estimated parameters by PSO are used to predict required joint torques for high accuracy tracking control. The effectiveness of some PSO methods for tracking control problem are verified...
A predictor-corrector entry guidance method satisfying the constraints of no-fly zone and waypoint is proposed in this paper. First, Gauss pseudospectral method is used to generate a reference trajectory. Based on the reference trajectory some reference points are selected which partition the entry process into several subsections. Then a predictor-corrector guidance law is developed. The trajectory...
In this paper, a footprint determination algorithm for entry vehicles based on three-dimensional acceleration profile is proposed, which solves the problem of fast determination of the entry coverage with complex multi-constraints. The aerodynamic adjustment capability is greatly improved since both the angle of attack and bank are regarded as primary variables, and in this way larger entry footprint...
The Five-hundred-meter Aperture Spherical Radio Telescope (FAST) requires high accuracy of positioning and attitude adjusting. Due to its flexible structure, the cable-cabin system can be excited to vibrate, which affects the performance. To alleviate the vibration during the slewing task, taking advantage of s-curve planning and input shaping, a cascade motion planning method is proposed. Considering...
For the omnidirectional lower-limb rehabilitation robot, a controller by using the acceleration and velocity information effectively of the target trajectory is proposed. The improved kinematics and dynamics model of the omnidirectional lower-limb rehabilitation robot with regard for centre-of-gravity shift are presented firstly. By including the acceleration and velocity information, the speed of...
The location of node is a research focus in wireless sensor networks (WSNs), and it is the foundation of the service based on the node location. In this paper, we propose a new localization method to improve the moving-baseline localization(MBL) performance by using second-order system. This method takes advantage of precise properties of MBL. We improve the localization accuracy by accurate fitting...
Under the coupling effect between guidance system and control system, the performance of traditional guidance and control method is limited. Therefore, integrated guidance and control (IGC) method is proposed to solve the problem. This method is characterized by the guidance loop and control loop which are considered as a whole part in accordance with the information of the relative motion between...
The mature analysis formula has been well used in the robotic forward kinematics for redundant manipulators, but the inverse-kinematics (IK) question is complex. Many methods have been adopted to resolve the complicated inverse-kinematics problem; for example, the previous pseudo-inverse based (PIB) method that have to calculate the computationally expensive inverse (specifically, pseudo-inverse)...
This paper presents a glideslope guidance method for autonomous rendezvous of spacecraft to approach, to fly around, and to depart from a target spacecraft in an elliptical orbit. The method is based on the closed-form solution of the Tschauner-Hempel(T-H) equations. The multi-impulse glideslope algorithms in the paper are general, capable of effect a translation motion of spacecraft in any direction...
An optimal impact angle control guidance law is proposed in this paper. The missile system is approximated under the small heading error assumption and the impact angle control guidance law is derived based on the approximated system to minimize the energy cost. The proposed guidance law has a form of biased PNG law and it's in accord with the previous result of PNG in the form acceleration command...
Modelling and simulation for aimed warhead anti-air missiles encountering targets has been researched. The second-order encounter model is carried out by least squares fitting based on control points, which is applied to solve the issues as low precision and poor adaptability of ideal linear encounter trajectory. For this model, a linear equivalent trajectory (LET) is proposed to reduce computation...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.