Hybrid-driven Mechanism Research Articles

Kinematics and Workspace Analysis of 5-DOF Hybrid Redundantly Driven Mechanism

A novel 5-DOF (5-SPS)+5R2U hybrid redun-dantly driven mechanism (HRDM for short) is proposed, which can realize 3 translations and 2 rotations (3T2R) movements. (5-SPS)+5R2U parallel mechanism is composed of six driving limbs. Of which 5-SPS (S represents spherical pair, P represents prismatic pair) limbs are symmetrically distributed at the center point of static and moving platform have no restriction on the degrees of freedom of the mechanism. The middle limb (7R)U (R represents revolute pair, U represents Hooke joint) is connected to the static platform and the center point of the moving platform. It is jointly driven by constant velocity motor and servo motor, and plays a role of restraining the freedom of the whole mechanism. It is called hybrid redundantly driven limb (HRDL for short). Hybrid-driven mechanism and redundantly actuated mechanism can be integrated into one mechanism by HRDL, which can give full play to the advantages of both. The inverse position solution model of the mechanism is established, and the velocity Jacobian matrix and acceleration expression are derived to obtain the velocity and acceleration variation laws of the me-chanism. On this basis, the factors affecting the workspace are analyzed, and the workspace atlas under different orientation angles is obtained. The results provide theoretical model for the realization planning trajectory of (5-SPS)+5R2U HRDM.

Kinematics and Workspace Atlas of 3-PSS/7R Hybrid Redundantly Driven Mechanism

Aiming at the problem that the traditional hybrid-driven mechanism is limited to planar mechanism, the paper presents a 3-PSS/7R Hybrid and Redundantly Driven Mechanism (HRDM for short), which takes advantage of hybrid driven and redundantly driven mechanism, driven by both constant velocity motor and servo motor. The mechanism consists of three PSS limbs with 6-DOF and a middle constrained limb with 7R configuration. The moving platform is constrained to 3-DOF motion. The kinematics model of the mechanism is established, and the kinematics analysis of 3-PSS/7R mechanism is carried out. The Jacobian matrix of the inverse kinematics is derived. The factors that affect the workspace are analyzed .The workspace of the HRDM is solved and verified using numerical method, and the workspace atlas with different orientation angles is obtained.

Stabilization of Networked Control Systems With Hybrid-Driven Mechanism and Probabilistic Cyber Attacks

This paper investigates the controller design problem of networked control systems subject to cyber attacks. A hybrid-triggering communication strategy is employed to save the limited communication resources. State measurements are transmitted over a communication network and may be corrupted by cyber attacks. The aim of this paper is to design a controller for a new closed-loop system model with consideration of randomly occurring cyber attacks and the hybrid-triggering scheme. A stability criterion is obtained for the system stabilization by employing Lyapunov stability theory and stochastic analysis techniques. Moreover, the desired controller gain is derived by resorting to some matrix inequalities. Finally, a numerical example is exploited to demonstrate the usefulness of the proposed scheme.

Research and experiment of a novel flower transplanting device using hybrid-driven mechanism

Aiming at decreasing the component complexity and cost of flower transplanting machine, an integrated transplanting method for picking and planting flower seedlings was proposed, and a hybrid-driven five-bar parallel mechanism was designed. A “beak-shaped” trajectory was designed for integrated transplanting requirements, and meantime, either the posture requirements of transplanting claw were determined. Based on the transplanting trajectory of the mechanism, a corresponding mathematical model for solving the link parameters was established, and then the five-bar mechanism was divided into two bar groups, optimization was conducted in two steps based on genetic algorithm and NSGA-II algorithm. Consequently, the optimal solution of the hybrid-driven five-bar parallel mechanism for flower seedling transplanting was obtained. Compared with similar designs, the trajectory displacement of the proposed mechanism is larger in the condition of smaller link size, which indicates that the mechanism can effectively decrease the machine size. The real-time controllable motor angular acceleration fluctuation is smaller and the commutation times are less, which has the advantage of reducing the difficulty of the mechanism control system. Subsequently, the correctness of the design method is verified by kinematics simulation. Finally, the synchronous linkage motion control methods of the two motors were designed, a transplanting experiment of the prototype was carried out, the picking success rate had reached 90%-93.4% and transplanting success rate was 80.5%-86.9% during experiment, which showed that the integrated operation of picking and planting flower seedlings can be realized by the proposed mechanism. Keywords: hybrid-driven mechanism, mechanism optimization, integrated operation of picking and planting, synchronous linkage motion control DOI: 10.25165/j.ijabe.20201302.5187 Citation: Zhao X, Zhang X S, Wu Q P, Dai L, Chen J N. Research and experiment of a novel flower transplanting device using hybrid-driven mechanism. Int J Agric & Biol Eng, 2020; 13(2): 92–100.

Hybrid-Driven Mechanism Based on Uncertain Network for Markov Jump System with Quantizations and Delay

This paper investigates the hybrid-driven mechanism problem for Markov jump system, where both channel quantization (BCQ) and network-induced delay based on uncertain network are considered. Firstly, comparing with the traditional event-triggered scheme, a hybrid-driven mechanism is employed in networked control systems (NCSs) for the finite capacity of communication bandwidth resources and system performance in equilibrium. Then, the quantization technology is applied in the communication channel from sensor-to-controller and controller-to-actuator. The application of BCQ is for further investigation that mitigate data packet transmission rate. Thirdly, Markov jump system is modeled for the hybrid-driven mechanism and network-induced delay. By constructing the Lyapunov–Krasovskii function, a sufficient condition is derived as the stability criterion, and the controller is designed in which the nonlinear term is rewritten for simplifying the calculation. Finally, two simulation examples are provided to demonstrate the effectiveness of the proposed approach.

Research and experiment of a novel flower transplanting device using hybrid-driven mechanism

Aiming at decreasing the component complexity and cost of flower transplanting machine, an integrated transplanting method for picking and planting flower seedlings was proposed, and a hybrid-driven five-bar parallel mechanism was designed. A “beak-shaped” trajectory was designed for integrated transplanting requirements, and meantime, either the posture requirements of transplanting claw were determined. Based on the transplanting trajectory of the mechanism, a corresponding mathematical model for solving the link parameters was established, and then the five-bar mechanism was divided into two bar groups, optimization was conducted in two steps based on genetic algorithm and NSGA-II algorithm. Consequently, the optimal solution of the hybrid-driven five-bar parallel mechanism for flower seedling transplanting was obtained. Compared with similar designs, the trajectory displacement of the proposed mechanism is larger in the condition of smaller link size, which indicates that the mechanism can effectively decrease the machine size. The real-time controllable motor angular acceleration fluctuation is smaller and the commutation times are less, which has the advantage of reducing the difficulty of the mechanism control system. Subsequently, the correctness of the design method is verified by kinematics simulation. Finally, the synchronous linkage motion control methods of the two motors were designed, a transplanting experiment of the prototype was carried out, the picking success rate had reached 90%-93.4% and transplanting success rate was 80.5%-86.9% during experiment, which showed that the integrated operation of picking and planting flower seedlings can be realized by the proposed mechanism. Keywords: hybrid-driven mechanism, mechanism optimization, integrated operation of picking and planting, synchronous linkage motion control DOI: 10.25165/j.ijabe.20201302.5187 Citation: Zhao X, Zhang X S, Wu Q P, Dai L, Chen J N. Research and experiment of a novel flower transplanting device using hybrid-driven mechanism. Int J Agric & Biol Eng, 2020; 13(2): 92–100.

Research Progress and Development Trend of Hybrid-driven Mechanism

Research Progress and Development Trend of Hybrid-driven Mechanism

Circling turning locomotion of a new multiple closed-chain-legs robot with hybrid-driven mechanism

A multi-legged robot based on a hybrid-driven mechanism is presented in this paper as an improvement of the legged robot based on crank-driven linkage mechanism. A hybrid-driven mechanism containing a full-rotational degree of freedom (DOF) and a linear translational DOF was obtained after a series of foot trajectory analyses on the Jansen mechanism. The stance phase trajectory of this hybrid-driven mechanism can maintain horizontality regardless of the length adjustment of the linear DOF. A turning gait of a hexapod robot based on this hybrid-driven mechanism was proposed, such that all of the legs had an identical crank angular speed, and the robot turned its orientation through different linear servo controls on the legs of the two sides. Simulation and experimental results showed that the hexapod robot could realize the turning gait when the legs of the two sides applied different length adjustments. The body center trajectories in all cases were approximate to a circle, and the smallest turning radius was close to the length of the robot. Moreover, the magnitude of the pitch and roll angles, and body center fluctuation in the simulations was all small, indicating that the hexapod robot based on the hybrid-driven mechanism was stable during the turning locomotion.

A New Hybrid-Driven Five-Bar Linkage Mechanism

A new two-degree-of-freedom hybrid-driven five-bar linkage mechanism is presented. The proposed linkage mechanism has two input links: one rotational input link and one linear input link, driven by a constant-speed motor and a servomotor, respectively. The rotational input link rotates with a constant angular speed, and the linear input link follows a reciprocating motion along a specified linear guide fixed on the rotational input link. The configuration was studied, and a kinematic analysis was performed. An example is provided to verify the feasibility and effectiveness of this methodology.

Iterative Learning Tracking Control of a Hybrid-Driven Based Three-Cable Parallel Manipulator

The aim of this work was to present iterative learning tracking control of a hybrid-driven based three-cable parallel manipulator (HDCPM). The HDCPM has the advantages of both cable parallel manipulator and hybrid-driven planar five-bar mechanism. Design of the HDCPM is described and dynamic model is developed on the basis of Lagrange method. Consider the HDCPM system with nonlinear, time-varying characteristics and repetitive unknown disturbances; an adaptive iterative learning control strategy, which can control gains change with the iterations, is designed. By means of Lyapunov function, the stability of the controller is proved. Finally, simulation results indicate that a perfect trajectory tracking of the HDCPM is achieved by the adaptive iterative learning controller, which also illustrate the correctness of the dynamic modeling and effectiveness of the proposed control strategy.

Integrated Mechanism Design and Control for Completely Restrained Hybrid-Driven Based Cable Parallel Manipulators

This paper deals with a methodology of simultaneous optimal design of mechanism and control for completely restrained hybrid-driven based cable parallel manipulators (HDCPM) in order to improve the dynamic performance of the HDCPM system. The HDCPM have the advantages of both the cable parallel manipulator and the hybrid-driven planar five-bar mechanism (HDPM). Kinematics and dynamics of the HDCPM are studied based on closed loop vector, geometric characteristic of mechanism and Lagrange method separately. Following that the integrated optimization model is established based on mechanics analysis and optimum control performance, and a genetic algorithm is used to carry out the optimization solution. As an example, separated optimization design and integrated optimization design for the completely restrained HDCPM with 3 Degrees of Freedom are comparatively investigated on the basis of the above design objectives. Simulation results illustrate that the dynamic performance of the HDCPM system can be significantly improved after integrated optimization design.

Study on the Trajectory Planning of Hybrid-Driven Planar 3-RRR Mechanism

Hybrid-driven mechanism synthesis the constant speed motor and the servo motor as the power source through a multi degree of freedom mechanism. The text study on the trajectory planning of hybrid-driven planar 3-RRR mechanism. Firstly, based on compatible link combinations, all possible basic configurations of planar 3-dof kinematics chains were derived. Based on the requirements of hybrid-driven mode, the kinematics chains were selected one by one Planar 3-RRR mechanism was determined to be the research object finally. Then, based on the conclusions of inverse kinematics analysis, using the cubic spline function on point to point path planning, the servo motor rotation laws were presented. Comparing the different speed situation of constant motor, the influence trends on planning results were analyzed.

Study on the Kinematics of Planar Two-DOF Hybrid-Driven Robot

The main research of planar two-DOF hybrid-driven robot is on the planar five-bar and the seven-bar mechanism, the planar two-DOF seven-bar mechanism is taken as the research object in this paper, the Assur Groups transformation method is used for the forward kinematics analysis of this seven-bar mechanism. The mathematical model of this mechanism is established for the forward kinematics analysis, and the COSMOSMotion is used for the kinematics and dynamics simulation of this hybrid-driven seven-bar mechanism.

Workspace Analysis of a Hybrid-Driven Cable Parallel Mechanism

This paper presents a new-type hybrid-driven cable parallel mechanism, which combines hybrid-driven mechanism with cable parallel mechanism, and the mechanism can not only operate with high speed, high accuracy, and high payload, but also have high performance output movement. The workspace of hybrid-driven cable parallel mechanism is characterized as the space where the end-effector can reach with tensions in all cables, and it is studied in this paper. Firstly, through the kinematic analysis, it can be derived the location equations of the end-effector. Then, the paper analyzes the main factors influencing the workspace of hybrid-driven cable parallel mechanism such as cable tension, workspace of hybrid-driven mechanism, the length of cables, and the motion range. At the end, with the location equations and constraints, the workspace is determined. Computational example is provided to demonstrate the effectiveness of the proposed analysis method.

Imitation Study of Hybrid-Driven Five-Bar Mechanism Output Movement Characteristic Based on Kinematics Analysis

Hybrid-driven five-bar mechanism that combines the motions of two characteristically different motors can attain the flexibility output movement. Its structure is simply and it has low cost. Therefore it is widely used manufacture fields. In this paper, the kinematics mathematic model of plane closed-loop five-bar mechanism is established according to the model-transforming method and closing-vector method. And expressions of its output movement parameters are attained. The output movement characteristic of hybrid-driven five-bar mechanism is imitated and studied. The results show that hybrid-driven five-bar mechanism which its geometry parameters confirmed can accomplish diversiform tasks through changing its input movement rule. Output movement track of hybrid-driven five-bar mechanism changes along with the original position of two input components changing. It indicates hybrid-driven five-bar mechanism can accomplish many group tasks at one time.

Seven-bar mechanical press with hybrid-driven mechanism for deep drawing; Part 2: Dynamic modeling and simulation

Modeling and dynamic analysis of the electromechanical coupling system of a hybrid-driven mechanical press were undertaken. A dynamic model of a two-degrees-of-freedom seven-bar linkage was developed using Lagrange’s equation. According to the equivalent circuit of a DC motor and a brushless servomotor, a dynamic model and negative feed-back model were separately developed. The fourth-order Runge-Kutta method, an explicit method, was employed as the integration technique in a computer simulation, and the time history of the hybrid-driven press was obtained.

Seven-bar mechanical press with hybrid-driven mechanism for deep drawing; Part 1: kinematics analysis and optimum design

The main feature of hybrid-driven linkage is the combination of the motion of a large constant velocity motor with that of a small servomotor via a two-degrees-of-freedom mechanism. Thereby, the hybrid-driven linkage can provide for programmable motion output. In the present study, a mechanical drawing press driven by a hybrid mechanism was optimized for displacement and velocity. An analysis of forward kinematics and an optimum model are presented. The actual displacement curves of the slider can approach the ideal ones by means of a two-step optimization. The dimensions of the linkage and the motion rules of the servomotor were optimized. The flexible features of the hybrid-driven drawing press are effectively demonstrated by three optimum examples. The optimum results validate the advantages of the hybrid-driven seven-bar mechanical press, such as its flexible slider speeds and adjustable strokes for drawing operations. By properly designing the input motion of the servomotor, the slider can pass through the desired trajectories.

Optimum Design of a Hybrid-Driven Mechanical Press Based on Inverse Kinematics

A novel hybrid-driven mechanical press for deep drawing is presented. The main feature of hybrid-driven linkage is to combine the motion of a large constant velocity motor with a small servomotor via a two degree of freedom mechanism. The former provides the main power and motion required, while the latter acts as a motion modulation device. Therefore, the hybrid-driven linkage can provide for programmable motion output. In this paper, a mechanical press driven by hybrid mechanism is developed that considers the displacement and velocity requirement of the drawing process. Inverse kinematic analysis and dimension synthesis optimization of this hybrid-driven mechanism is presented, which points out a new way for press research and provides a new method for press application in flexible manufacture.

Dynamics modeling and simulation of a new nine-bar press with hybrid-driven mechanism

A novel hybrid-driven mechanical press for precision drawing is presented. This new press is composed of a nine-bar linkage which has two degrees of freedom determined by inputs from a dc constant speed motor and a dc servomotor. Therefore, the generalized coordinates are the angular displacement of two cranks. The kinetic energy, potential energy and generalized torques are analyzed. According to the equivalent circuit of the dc motor and the brushless servomotor, their dynamical model and position negative feedback model are developed separately. Then, a dynamical model for the hybrid-driven press is developed by using Lagrange’s formulation. The dynamical equation is then transformed into a system of first order equations. Six first order differential equations are obtained in the state variables. In the end, the fourth fourth order Runge-Kutta method, an explicit method, is chosen as the integration technique of computer simulation. Two motors’ current, two cranks’ position and two cranks’ angular velocity are treated as unknowns and the time response of the hybrid-driven press is obtained by integrating the system of first order equations through time.