René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"线性化","articleBody":"你好，我在作者给的非线性动力学模型 线性化 案例中，按照给的代码，运行总是会出现类型不匹配的错误，运行了作者的代码也是同样的问题，请问是为什么呢\r\n作者代码如下：\r\nmc = 0.2 # mass of the cart (kg)\r\nmp = 0.1 # mass of the pole (kg)\r\nℓ = 0.5 # distance to the center of mass (meters)\r\ng = 9.81\r\n# \r\n\r\ndef cartpole_dynamics(x, u):\r\n    r       = x[0] # cart position\r\n    theta   = x[1] # pole angle\r\n    rd      = x[2] # change in cart position\r\n    theta_d = x[3] # change in pole angle\r\n    F       = u[0] # force applied to cart\r\n\r\n#问题出现处，显示np.sin(theta)中的theta不符合数据要求\r\n    theta_dd = (g*np.sin(theta) + np.cos(theta) * ((-F - mp*l*(theta_d**2) * \\\r\n                    np.sin(theta))/(mc + mp))) / (l*(4/3 - (mp*(np.cos(theta)**2))/(mc + mp)))\r\n    rdd = (F + mp*l*((theta_d**2)*np.sin(theta) - theta_dd*np.cos(theta))) / (mc + mp)\r\n\r\n    return np.array([rd, theta_d, rdd, theta_dd])\r\ndef cartpole_rk4(x, u, dt):\r\n    f1 = dt*cartpole_dynamics(x, u)\r\n    f2 = dt*cartpole_dynamics(x + f1/2, u)\r\n    f3 = dt*cartpole_dynamics(x + f2/2, u)\r\n    f4 = dt*cartpole_dynamics(x + f3, u)\r\n    return x + (1/6)*(f1 + 2*f2 + 2*f3 + f4)\r\nimport autograd as AG\r\n\r\nxgoal = np.array([0.0, np.pi, 0.0, 0.0])\r\nugoal = np.array([0.0])\r\n\r\ndt = 0.01\r\n\r\nA = AG.jacobian(lambda x_: cartpole_rk4(x_, ugoal))(xgoal)\r\nB = AG.jacobian(lambda u_: cartpole_rk4(xgoal, u_))(ugoal)","author":{"url":"https://github.com/fly-daiuser","@type":"Person","name":"fly-daiuser"},"datePublished":"2024-09-29T14:47:20.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/3/tinympc-python/issues/3"}