美国波士顿公司BigDog机器人简介.ppt

1、BigDog OverviewNovember 22,20082008 Boston Dynamics Engine Leopard go-kart engineOne cylinder Two stroke Water cooled 9,000 rpm 15 hp Electric starter Hydraulic SystemVariable displacement hydraulic pump(3,000 psi)Custom actuator package(x16)Low-friction hydrodynamic seals 2-stage electro-hydraulic

2、servovalve Position sensor Force sensor Heat exchanger Various filters,manifolds,accumulators,and valves Hydraulic Actuator PackageHydraulic SystemHeat Exchanger 9.62 lbs Engine/Drive/Pump:26 lbs/1.42 lbs/6.5 lbs Fuel tank/Fuel:2.1 lbs/10.4 lbs Oil tank:3.6 lbs Sensors BigDog Sensors Type Quantity L

3、ocation N Proprioception Exteroception Homeostasis Onboard Computer PC104 stack Pentium CPU QNX real-time OS Code:C+Custom I/O interface boards Functions Performed:Control Sensing Data Collection Communications Electric Power Distribution Software ArchitectureSoftware Processes Function:Control Serv

4、o Logging Description:Main process.Balances and steers robot,odometry,communicates with operator.Joint control,read sensors,command actuators,engine control.Log engineering data for performance development and failure analysis.Update Frequency:200 Hz 1,000 Hz 200 Hz Vest OperatorControl Unit(OCU)Con

5、trol Principles Support-Bounce on springy legs Balance-Move legs with symmetry to achieve balance Posture-Keep body level using stance legs Control BigDog Maintain Body Posture Control of body posture through force control Control BigDog Maintain Body Posture Control of body posture through force co

6、ntrol Maintain Ground Contact Force control through compliant leg shock Control BigDog Maintain Body Posture Control of body posture through force control Maintain Ground Contact Force control through compliant leg shock Maintain Lateral Balance Place feet to control body lateral velocity Stance leg

7、 motion predicts lateral veloc.and accel.for New stance swing leg placement Additional ControlsEstimate ground plane using history of leg kinematic data and odometry Adjust posture to optimize leg strengtwhile maintaining reach on terrainUse traction control to avoid,detect and recover from foot sli

8、ps Move legs to avoid leg collisions Determine ego-motion using kinematic,inertial and visual odometry Trot Control Features Engine Power Control.Engine RPM regulated in response to actual and predicted load.Ground steepness,ground roughness,and lateral body velocity predict demand.Leg Collision Avo

9、idance.Adjacent legs have overlapping workspace.Swing leg trajectories avoid hitting adjacent stance legs.Trot ControlX Closed loop.Speed error corrected by x direction foot forces.Y Lateral foot position chosen to offset unwanted lateral body velocity.Coupled ControllerCorrections for height and Euler errors map to y and z direction foot forces.ZRollPitch YawLIDAR Leader Tracking Follow leader without direct driving and without GPS:Leader wears retro-reflective marker SICK LIDAR used to locate leader and generate steering signals BigDog follows at approximate fixed distance