pressure_observer.h

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 *  \author Joe Romano
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//@author  Joe Romano
//@email   joeromano@gmail.com
//@brief   pressure_observer.h
 
#include <pr2_hardware_interface/hardware_interface.h>
#include <pr2_gripper_sensor_msgs/PR2GripperPressureData.h>
#include <pr2_gripper_sensor_controller/digitalFilter.h>
 
#ifndef _PRESSURE_OBSERVER
#define _PRESSURE_OBSERVER
 
#define UNITS_PER_N 1600
 
class pressureObserver{
  
  public:
    // functions
    pressureObserver(pr2_hardware_interface::PressureSensor* left,pr2_hardware_interface::PressureSensor* right);    // constructor
    ~pressureObserver();                                // default destructor
    void spin();                                        // method to update sensor data. should run at 1khz
    bool graspContact(int contactsDesired);             // detects finger impacts
    void updateZeros2();                                // method to update our zero value offsets (zero_offset)
    bool checkPlaceContact(double dF);                  // method to look for impact slip and return true
    bool checkSlip(double slip_motion_limit = 0.007, double slip_force_limit = 0.18);
    int  checkSideImpact(double dF);                    // method to check for side impacts on finger sensors
    void updateBrokenSensorStatus();
 
 
    double padForce_cur;                                // fingerpad force average between both fingers
    double padForce_cur_nonbiased;                      // force average from the non-biased pressures
    double padForce_left_cur, padForce_left_prev;       // current cumulative force on our left/rigth fingerpads
    double padForce_left_cur_nonbiased;
    double padForce_right_cur, padForce_right_prev;     // previous cumulative force on our left/right fingerpads
    double padForce_right_cur_nonbiased;
    double totalLoading_left, totalLoading_right;       // total dynamic laoding on our left/right pads
    double totalLoading,totalLoading_prev;              // left and right loading average
    double cellLoading_left, cellLoading_right;         // cellular loading on the left/right fingers
    double forceLightest;
    double hpForceTrigger;
    double lfForce_left, lfForce_right;
    bool broken_sensor;                                 // flag to indicate we may have a broken sensor
    bool left_contact, right_contact;                   // flags to indicate whether a left or right contact happened
    bool placeContact;
    
    // storage of our pressure sensor state information. _now is the most recent raw data. _prev is the last subsampled value
    // _current is the current subsampled value
    pr2_gripper_sensor_msgs::PR2GripperPressureData  pressure_now, pressure_prev, pressure_current;
    pr2_gripper_sensor_msgs::PR2GripperPressureData  pressure_thresh_now, pressure_thresh_prev, pressure_thresh_current;
    pr2_gripper_sensor_msgs::PR2GripperPressureData  pressure_prev_zerod, pressure_current_zerod;
    pr2_gripper_sensor_msgs::PR2GripperPressureData  pressure_prev_bias, pressure_cur_bias;
    pr2_gripper_sensor_msgs::PR2GripperPressureData  pressure_bp;
 
    digitalFilter *pressureLFFilt_left[22];
    digitalFilter *pressureLFFilt_right[22];
 
 
  private:
    void getPadCentroid(boost::array<double,22> pressureArray, double *x, double *y);
    void updateXYCentroids();
    bool updatePressureState();                         // method to acquire new data from both fingers and apply appropriate subsampling 
    void updateTotalLoading();                          // method to update the toal loading of each finger totalLoad_left _right
    void zero();                                        // method to zero out data
    void bias_estimator();                              // remove mean bias for near zero data
    double getPadForce(boost::array<double,22> pressureArray);  // translate fingertip pressure vector to cumultive sum on the fingerpad (just the pad)
    void updateContactState();                          // update the state of the robots contact sensors
 
 
    pr2_hardware_interface::PressureSensor* left_finger;// a copy of our pressure sensor handle
    pr2_hardware_interface::PressureSensor* right_finger;// a copy of our pressure sensor handle
 
    int subSample_cnt;                                  // a counter to keep track of how many samples we ignored during subsampling
    int subSample_steps;                                // 1+ the number of values to skip during subsampling
    int zero_samples;                                   // the number of samples to use when trying to evaluate our zero offset
    int zero_cnt;                                       // counter to keep track of how many samples we've stored for zero estimation
    pr2_gripper_sensor_msgs::PR2GripperPressureData zero_offset;// a storage container for our zero offset values
 
    double time_prev, time_cur;                         // stroage containers for the previous and current pressure update times
    double dt;                                          // the time expired between pressure update iterations
 
};
 
 
 
#endif // _PRESSURE_OBSERVER