从超类继承时实现matlab.system的疑难解答

我正在尝试将一个matlab类实现到simulink matlab系统中。当我实现超类时，模拟工作正常，但是使用子类我得到以下错误：

“Simulink无法自动推断“子类系统”的输出信号属性。Simulink使用代码生成技术自动确定系统对象的输出信号属性。系统对象“子类”包含不支持代码生成的代码。 错误是 '未定义的函数或变量'obj'。局部变量的第一个赋值决定其类别。' MATLAB系统块“Subclass System”发生错误。请参阅文件“superclass.m”第29行第28列。该错误是在大小传播阶段检测到的。”

我在下面的代码中注释了这一行

我必须指定一些额外的内容吗

下面是子类定义：

classdef subclass < superclass
    properties(Access = protected) % These variables must be initialised. Here or in the setupImpl function
    end

    methods (Access=protected)
        function resetImpl(obj)
        end

        %% Common functions
        function setupImpl(obj)
            % Perform one-time calculations, such as computing constants
            setupImpl@superclass();
            %obj.initFilter(obj.sampleTime, obj.delta_i, obj.delta_d, obj.g_mps2, obj.q0, obj.b_w0, obj.sigma_2_w, obj.sigma_2_a, obj.sigma_2_b_w, obj.sigma_2_yaw)
        end

        function attitude = stepImpl(obj,u, y)
            % Implement algorithm.
            attitude = 5;
        end
    end

    methods

        % Constructor must be empty for matlab.System. In Matlab call
        % initFilter after the object was created. In simulink setupImpl()
        % will be called
        function obj = subclass()
            obj@superclass();
        end
    end

end

classdef superclass < matlab.System


    % These variables must be initialized in the simulink model
    properties
        sigma_2_w;
        sigma_2_a;
        sigma_2_b_w;
        sigma_2_yaw;
    end

    properties(Access = protected) % These variables must be initialised. Here or in the setupImpl function
        R;
        Q;
    end

    methods (Access = protected)

        function resetImpl(obj)
        end

        %% Common functions
        function setupImpl(obj)
            % Perform one-time calculations, such as computing constants
            obj.Q  = diag([obj.sigma_2_w',obj.sigma_2_b_w']); % this is line 29
            obj.R = diag([obj.sigma_2_a',obj.sigma_2_yaw']); 
        end

        function attitude = stepImpl(obj,u, y)
            % Implement algorithm.
            attitude = 5;
        end
    end

    methods

        % Constructor must be empty for matlab.System. In Matlab call
        % initFilter after the object was created. In simulink setupImpl()
        % will be called
        function obj = superclass()
             % Support name-value pair arguments when constructing object
        end
    end
end

classdef子类

这里是超类定义：

classdef subclass < superclass
    properties(Access = protected) % These variables must be initialised. Here or in the setupImpl function
    end

    methods (Access=protected)
        function resetImpl(obj)
        end

        %% Common functions
        function setupImpl(obj)
            % Perform one-time calculations, such as computing constants
            setupImpl@superclass();
            %obj.initFilter(obj.sampleTime, obj.delta_i, obj.delta_d, obj.g_mps2, obj.q0, obj.b_w0, obj.sigma_2_w, obj.sigma_2_a, obj.sigma_2_b_w, obj.sigma_2_yaw)
        end

        function attitude = stepImpl(obj,u, y)
            % Implement algorithm.
            attitude = 5;
        end
    end

    methods

        % Constructor must be empty for matlab.System. In Matlab call
        % initFilter after the object was created. In simulink setupImpl()
        % will be called
        function obj = subclass()
            obj@superclass();
        end
    end

end

classdef superclass < matlab.System


    % These variables must be initialized in the simulink model
    properties
        sigma_2_w;
        sigma_2_a;
        sigma_2_b_w;
        sigma_2_yaw;
    end

    properties(Access = protected) % These variables must be initialised. Here or in the setupImpl function
        R;
        Q;
    end

    methods (Access = protected)

        function resetImpl(obj)
        end

        %% Common functions
        function setupImpl(obj)
            % Perform one-time calculations, such as computing constants
            obj.Q  = diag([obj.sigma_2_w',obj.sigma_2_b_w']); % this is line 29
            obj.R = diag([obj.sigma_2_a',obj.sigma_2_yaw']); 
        end

        function attitude = stepImpl(obj,u, y)
            % Implement algorithm.
            attitude = 5;
        end
    end

    methods

        % Constructor must be empty for matlab.System. In Matlab call
        % initFilter after the object was created. In simulink setupImpl()
        % will be called
        function obj = superclass()
             % Support name-value pair arguments when constructing object
        end
    end
end

classdef超类

我发现了错误。在子类的setupImpl函数中，我必须使用obj作为参数调用超类的setupImpl：

setupImpl@Superclass(obj);

这是我的构造函数。这里我没有使用obj作为返回值

function obj = Subclass()
    obj = obj@Superclass();
end

---

我发现了错误。在子类的setupImpl函数中，我必须使用obj作为参数调用超类的setupImpl：

setupImpl@Superclass(obj);

这是我的构造函数。这里我没有使用obj作为返回值

function obj = Subclass()
    obj = obj@Superclass();
end

---

如果你根本没有构造函数会发生什么？如果你根本没有构造函数会发生什么？