用car进行悬架仿真的时候，轮子和测试台不接触是怎么回事？

狗耳

本人最近自己做了一个双连杆后悬架的模型，但是在进行悬架仿真的时候，发现测试台和轮子开始的时候并不接触，我设计的跳动范围是-100～100，差不多在-100到0之间他们是没有接触的，到后来才接触。这是不是通讯器没有建好的原因？还是有其他方面的原因？

    打开文件的信息是这样的：
Opening the assembly: 'doublelink_assy'...
Opening the rear suspension subsystem: 'doublelink'...
Assembling subsystems...
Assigning communicators...
WARNING: The following input communicators were not assigned during assembly:
     testrig.cil_jack_frame (attached to ground)
     testrig.cir_jack_frame (attached to ground)
     testrig.cis_driveline_active
     testrig.cis_leaf_adjustment_steps
     testrig.cis_powertrain_to_body (attached to ground)
     testrig.cis_steering_rack_joint
     testrig.cis_steering_wheel_joint
     testrig.cil_diff_tripot
     testrig.cir_diff_tripot
     testrig.cil_suspension_upright (attached to ground)
     testrig.cir_suspension_upright (attached to ground)
     doublelink.cil_subframe_front_to_body (attached to ground)
     doublelink.cir_subframe_front_to_body (attached to ground)
     doublelink.cil_subframe_rear_to_body (attached to ground)
     doublelink.cir_subframe_rear_to_body (attached to ground)
     doublelink.cil_strut_to_body (attached to ground)
     doublelink.cir_strut_to_body (attached to ground)
     doublelink.cil_trail_to_body (attached to ground)
     doublelink.cir_trail_to_body (attached to ground)
Assignment of communicators completed.
Assembly of subsystems completed.
Suspension assembly ready.

在接下来的仿真过程中，有这样一条警告：
---- WARNING ----
   Actuator reached lower force limit
   ID = 2

请各位大虾指点迷津！

liuzk113