Cannot read property of send of undefined

1

In my ember 1.9.1 (EAK) app, am using queryParams to navigate between pages and for updating corresponding url on clicking corresponding button. The view get rendered if I click the button for first time, but if I refresh the page, am getting “Cannot read property of send of undefined” In my approute.js I’ve something like,

queryParams: {category: {refreshModel:true}},
------model----
actions: { queryParamsDidChange: function(){
                        var self = this;
                        console.log("CONTROLLER " + this.controller);
                        self.controller.send('resetListObj'); // No I18N
                        self.controller.send('resetPageObj'); // No I18N                     
                        self.refresh();
                } }

My appcontroller.js has something like

queryParams: ['category'], // No I18N
    category: 'all', // No I18N

My controller becomes undefined if I refresh the page.