AngularJS: tracking which checkbox is checked

In an HTML form, I need to track which checkboxes get checked so I can insert it in my query object that is to be posted to the backend.

I have the following three checkboxes in an array in the $scope:

$scope.typeCheckBoxes = [
      {label: "A", val: true},
      {label: "B", val: false},
      {label: "C", val: false}
    ];

and this below is my template for rendering the checkboxes in the form:

<span ng-repeat="chk in typeCheckBoxes">
<input type="checkbox" ng-model="chk.val" id="chk.label" ng-change="addType(this)" />
            <label>{{chk.label}}</label>
</span>

and in my controller, I tried to create the function addType() to add the checked checkbox to my query object:

$scope.queryObj = {
types: []
};

$scope.addType = function(e) {
   var selectedBox = angular.element(e.id); // not working
   if (selectedBox) {
     $scope.queryObj.types.push(selectedBox);
   }

};

However, I am not sure how I can get the id of the checked checkbox. your help is appreciated very much.