Cannot read property of send of undefined

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

My appcontroller.js has something like

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

My controller becomes undefined if I refresh the page.