replace tcp_accuracy_checker with hash comparison

This closes #34

ur_rtde_driver/src/ur/calibration_checker.cpp

@@ -0,0 +1,47 @@
+// this is for emacs file handling -*- mode: c++; indent-tabs-mode: nil -*-
+
+// -- BEGIN LICENSE BLOCK ----------------------------------------------
+// -- END LICENSE BLOCK ------------------------------------------------
+
+//----------------------------------------------------------------------
+/*!\file
+ *
+ * \author  Felix Mauch mauch@fzi.de
+ * \date    2019-06-14
+ *
+ */
+//----------------------------------------------------------------------
+
+#include <ur_rtde_driver/ur/calibration_checker.h>
+
+namespace ur_driver
+{
+CalibrationChecker::CalibrationChecker(const std::string& expected_hash)
+  : expected_hash_(expected_hash), checked_(false)
+{
+}
+bool CalibrationChecker::consume(std::shared_ptr<comm::URPackage<primary_interface::PackageHeader>> product)
+{
+  auto kin_info = std::dynamic_pointer_cast<primary_interface::KinematicsInfo>(product);
+  if (kin_info != nullptr)
+  {
+    // LOG_INFO("%s", product->toString().c_str());
+    //
+    if (kin_info->toHash() != expected_hash_)
+    {
+      LOG_ERROR("The calibration parameters of the connected robot don't match the ones from the given kinematics "
+                "config file. Please be aware that this can lead to critical inaccuracies of tcp positions. Use the "
+                "ur_calibration tool to extract the correct calibration from the robot and pass that into the "
+                "description. See [TODO Link to documentation] for details.");
+    }
+    else
+    {
+      LOG_INFO("Calibration checked successfully.");
+    }
+
+    checked_ = true;
+  }
+
+  return true;
+}
+}  // namespace ur_driver