test: fix initialization of some tests

Author: AayushSabharwal

test/input_output_handling.jl

@@ -128,16 +128,17 @@ eqs = [connect(torque.flange, inertia1.flange_a)
        connect(inertia2.flange_a, spring.flange_b, damper.flange_b)
        y ~ inertia2.w + torque.tau.u]
 model = ODESystem(eqs, t; systems = [torque, inertia1, inertia2, spring, damper],
-    name = :name)
+    name = :name, guesses = [spring.flange_a.phi => 0.0])
 model_outputs = [inertia1.w, inertia2.w, inertia1.phi, inertia2.phi]
 model_inputs = [torque.tau.u]
+op = Dict(torque.tau.u => 0.0)
 matrices, ssys = linearize(
-    model, model_inputs, model_outputs);
+    model, model_inputs, model_outputs; op);
 @test length(ModelingToolkit.outputs(ssys)) == 4
 
 if VERSION >= v"1.8" # :opaque_closure not supported before
     let # Just to have a local scope for D
-        matrices, ssys = linearize(model, model_inputs, [y])
+        matrices, ssys = linearize(model, model_inputs, [y]; op)
         A, B, C, D = matrices
         obsf = ModelingToolkit.build_explicit_observed_function(ssys,
             [y],
@@ -321,7 +322,8 @@ function SystemModel(u = nothing; name = :model)
                 u
             ])
     end
-    ODESystem(eqs, t; systems = [torque, inertia1, inertia2, spring, damper], name)
+    ODESystem(eqs, t; systems = [torque, inertia1, inertia2, spring, damper],
+        name, guesses = [spring.flange_a.phi => 0.0])
 end
 
 model = SystemModel() # Model with load disturbance
@@ -410,7 +412,8 @@ matrices, ssys = linearize(augmented_sys,
         augmented_sys.u,
         augmented_sys.input.u[2],
         augmented_sys.d
-    ], outs)
+    ], outs;
+    op = [augmented_sys.u => 0.0, augmented_sys.input.u[2] => 0.0, augmented_sys.d => 0.0])
 @test matrices.A ≈ [A [1; 0]; zeros(1, 2) -0.001]
 @test matrices.B == I
 @test matrices.C == [C zeros(2)]

test/split_parameters.jl

@@ -165,15 +165,16 @@ function SystemModel(u = nothing; name = :model)
             systems = [torque, inertia1, inertia2, spring, damper, u])
     end
     ODESystem(eqs, t; systems = [torque, inertia1, inertia2, spring, damper],
-        name)
+        name, guesses = [spring.flange_a.phi => 0.0])
 end
 
 model = SystemModel() # Model with load disturbance
 @named d = Step(start_time = 1.0, duration = 10.0, offset = 0.0, height = 1.0) # Disturbance
 model_outputs = [model.inertia1.w, model.inertia2.w, model.inertia1.phi, model.inertia2.phi] # This is the state realization we want to control
 inputs = [model.torque.tau.u]
+op = [model.torque.tau.u => 0.0]
 matrices, ssys = ModelingToolkit.linearize(
-    wr(model), inputs, model_outputs)
+    wr(model), inputs, model_outputs; op)
 
 # Design state-feedback gain using LQR
 # Define cost matrices