A study is devoted to the delay robust stability for linear system with time delay, using matrix analysis and comparison theory on differential integral difference equations. Since the matrix norm used to derive...A study is devoted to the delay robust stability for linear system with time delay, using matrix analysis and comparison theory on differential integral difference equations. Since the matrix norm used to derive the results may be arbitrary consistent matrix norm, the obtained results possess some agility, and it makes quite convenient to check stability for linear systems with time delay. In particular, a sufficient and necessary condition for delay robust stability is obtained, and a formula to calculate the maximum delay for systems with stability is given. At the end, the results are used to analyze a flight control system (FCS). Comparison with some literature shows that the criteria in this paper are not only simple, but also of small conservativeness.展开更多
At Shanghai Jiao Tong University（SJTU） we have established a research laboratory for advanced acceleration research based on high-power lasers and plasma technologies. In a primary experiment based on the laser wake...At Shanghai Jiao Tong University（SJTU） we have established a research laboratory for advanced acceleration research based on high-power lasers and plasma technologies. In a primary experiment based on the laser wakefield acceleration（LWFA） scheme, multi-hundred Me V electron beams of reasonable quality are generated using 20–40 TW, 30 femtosecond laser pulses interacting independently with helium, neon, nitrogen and argon gas jet targets. The laser-plasma interaction conditions are optimized for stabilizing the electron beam generation from each type of gas. The electron beam pointing angle stability and divergence angle as well as the energy spectra from each gas jet are measured and compared.展开更多
文摘A study is devoted to the delay robust stability for linear system with time delay, using matrix analysis and comparison theory on differential integral difference equations. Since the matrix norm used to derive the results may be arbitrary consistent matrix norm, the obtained results possess some agility, and it makes quite convenient to check stability for linear systems with time delay. In particular, a sufficient and necessary condition for delay robust stability is obtained, and a formula to calculate the maximum delay for systems with stability is given. At the end, the results are used to analyze a flight control system (FCS). Comparison with some literature shows that the criteria in this paper are not only simple, but also of small conservativeness.
基金Supported by 973 National Basic Research Program of China(2013CBA01504)Natural Science Foundation of China NSFC(11121504,11334013,11175119,11374209)
文摘At Shanghai Jiao Tong University（SJTU） we have established a research laboratory for advanced acceleration research based on high-power lasers and plasma technologies. In a primary experiment based on the laser wakefield acceleration（LWFA） scheme, multi-hundred Me V electron beams of reasonable quality are generated using 20–40 TW, 30 femtosecond laser pulses interacting independently with helium, neon, nitrogen and argon gas jet targets. The laser-plasma interaction conditions are optimized for stabilizing the electron beam generation from each type of gas. The electron beam pointing angle stability and divergence angle as well as the energy spectra from each gas jet are measured and compared.
