test: fix initialization of model in tests

Author: AayushSabharwal

test/input_output_handling.jl

@@ -128,10 +128,11 @@ 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 => 1.0])
 model_outputs = [inertia1.w, inertia2.w, inertia1.phi, inertia2.phi]
 model_inputs = [torque.tau.u]
-matrices, ssys = linearize(model, model_inputs, model_outputs);
+matrices, ssys = linearize(
+    model, model_inputs, model_outputs; op = Dict(torque.tau.u => 0.0));
 @test length(ModelingToolkit.outputs(ssys)) == 4
 
 if VERSION >= v"1.8" # :opaque_closure not supported before

test/split_parameters.jl

@@ -164,14 +164,16 @@ function SystemModel(u = nothing; name = :model)
             t;
             systems = [torque, inertia1, inertia2, spring, damper, 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 => 1.0])
 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]
-matrices, ssys = ModelingToolkit.linearize(wr(model), inputs, model_outputs)
+matrices, ssys = ModelingToolkit.linearize(
+    wr(model), inputs, model_outputs; op = Dict(model.torque.tau.u => 0.0))
 
 # Design state-feedback gain using LQR
 # Define cost matrices