Q. Zhang's research while affiliated with Shanghai Jiao Tong University and other places

Based on partial balancing the design for control (DFC) method was presented in order to improve kinematic and dynamic performance of single-freedom closed-loop mechanism which is actuated by servomotors. This design method suggests a mass-redistribution scheme (prior to designing controllers), which follows the principle of a partial inertial force balancing scheme, for the modification of an existing mechanism, with the aim to optimize the system dynamic model and thus to facilitate the controller design. By taking a slider-crank mechanism as an example, the proposed DFC method was applied to design the mechanism. The simulation results were given to verify the effectiveness of the presented method.

This paper presents a simple and effective method to solve the position of higher-class Assur groups by means of virtual variable searching. It transforms the higher-class Assur groups into a constraint link, Class II Assur group(s), and virtual driving link(s), defined by the virtual variable. The constraint link is reassembled by one-dimensional searching of the virtual variable, and the potential solutions of the position of the higher-class Assur group are achieved with rapid mathematic convergence. Detailed criteria are set up for complicated higher-class Assur groups, including how to select the virtual driving link and constraint Link, and how to decide the solving sequence of converted Class II Assur groups. A versatile visual program has been developed to simulate higher-class planar mechanisms. Finally, an example of the feeding mechanism of a multifunction domestic sewing machine demonstrates the new method.

This paper discussed the definition and connotation of the conceptual design of mechanical products. It analyzed the relation between the needs of market and the functions of products. It studied the method of concept design of mechanical products based on the technological action process, and the method of establishment of domain knowledge based on the basic characteristic of action. It inquired into the practical method of creative concept design of mechanical products. It also studied the method and key technology of computer aided conceptual design for mechanical products, and put forward the conclusion that the conceptual design for mechanical products should establish the function design model and mechanical movement scheme based on the basic characteristics of mechanism system.

This paper presented a simple and effective method to solve the position of higher class Assur groups by the method of quick searching method based on constraint link. It transforms higher class Assur group to one constraint link, Class II Assur group (s), and virtual driving link defined by the virtual variable, and sets up the function relationship between position parameters of converted Class II Assur group (s) and virtual variable. Based on the assembly condition of constraint link, the optimization goal is formed. Applying one-dimensional searching technology, the potential solutions of the position of the higher class Assur group are achieved with rapid mathematic convergence. This method is applicable for arbitrary complex Assur groups, and is convenience for use. The principle and procedure of the proposed method were shown. A versatile visual program was developed to simulate higher class planar mechanisms. Finally, an example of the feeding mechanism of multifunction domestic sewing machine with a RR-RP-PR Class I Assur group was illustrated to demonstrate the new method.

The three subsystems composition theory for mechatronic systems and their interrelationships were analyzed. DPAM-F design model for generalized mechanism sub-system of mechatronic systems was studied. Utilizing the merits of artificial intelligence programming language SICStus Prolog, the DPAM-F design model was computerized. The essential software platform for intelligentized scheme generation of generalized mechanism was built. The practical application of this design model was illustrated through scheme generation and automatic simulation of thread-cutting mechanism in sewing machine, and the experiment arrives at a good result.

Objective: To observe the effects of glutamate on the afferent discharges of dorsal cutaneous sensory nerves in rats. Methods: By using the single unit recording on isolated nerve filaments in the spinal nerve dorsal cutaneous branches in vivo, the effects of glutamate injection into the cutaneous receptive field of sensory nerves on primary afferent discharges were observed. Results: Injection of 10 μl monosodium glutamate (0.3 mmol/L), a glutamate receptor agonist, significantly increased the mean discharge rate of Aδ and C units either during 7 min injection or 10 min post-injection as compared with pre-injection group (P <0.05), but did not affect the afferent discharge rate of the Aβ units (P > 0.05). The glutamate excitatory effects on the discharge rate of Aδ and C primary afferent terminal covered over all periods observed. Conclusion: Glutamate, as a neurotransmitter, may be involved in the peripheral sensitization of pain.

The mobility is analyzed for the 4R1P-type planar closed-loop five-bar linkages using characteristics charts and four-bar Grashof criterion by introducing the virtual link. Based on dimensional relations of the three RR-type links, the five-bars are divided into three categories: Class I, Class II and Class III. Class I satisfies rmax < rmid + rmin , Class II satisfies rmax > rmid + rmin and Class III holds the equality. In the characteristics charts, Class I has a circular slide reachable range with two Grashof regions and two non-Grashof ones separated by three Grashof boundaries C1 , C2 and C3 , as well as one structure boundary B3 ; Class II has a ringed range with one Grashof region and two non-Grashof ones separated by the void boundary A1 instead of C1 , two Grashof boundaries C2 and C3 , as well as B3 ; and Class III has a circular range with three regions separated by C2 , C3 and B3 . From the four-bar Grashof criterion, the five-bars have two fully revolute joints at the Grashof regions while no such joints at the non-Grashof regions. Specially, the five-bars have Grashof change points at the Grashof boundaries and keep in line at A1 and B3 . Each class includes further sub-classes. Several cases are illustrated for the applications.