“…The true values of the uncertain parameters of systems ( 38) and ( 39) are chosen as σ = 10, r = 28, β = 8/3 and a = 35, b = 3, c = 28. According to the previous analysis results in the section, if k, γ 11 , γ 21 , γ 12 , γ 22 are chosen as k = γ 11 = γ 21 = −1 and γ 12 = γ 22 = 0.01, GFPS between uncertain Lorenz and Chen chaotic systems will be achieved under the control of the controller (40), and the uncertain parameters will be estimated using the parameter update laws (41) and (42). The initial conditions are given by x 1 (0) = 0.1, x 2 (0) = 0.2, x 3 (0) = 0.3, y 1 (0) = 0.4, y 2 (0) = 0.5, y 3 (0) = 0.6, σ = 9, r = 25, β = 3, â = 33, b = 2 and ĉ = 29 to perform the numerical simulations.…”