Controls as part of human-machine interface can have a different degree of importance in the dialogue between the operator and the equipment or machine.
Standardization requirements (including ergonomic) to controls is particularly important in areas where the adoption of measures to ensure security, it is essential (for example, as a result of improper operation of system actuation of accident can happen or when you need frequent or prompt action in the operation of cranes, operation of vehicles, etc.), especially in cases where potentially dangerous equipment used by people with low skills.
Requirements for management bodies and principles of actuation human-machine interface are defined in the international standard IEC 60447:2004 "Interface human-machine (HMI). Principles of actuation", which is among the basic publications on security adopted by the International electrotechnical Commission This standard is intended to apply the relevant Technical committees of the IEC in the development of standards on specific equipment, as well as in cases when there are no standards for specific equipment with a similar scope.
Classification of management bodies
1 single-function controls: One or more controls, the result of which leads to one final result (for example, moving in a certain direction or location).
2 multi-function controls: One or more controls, the result of which leads to various outcomes (for example, moving in a specific direction and location).
The management body may be in the form of knobs, buttons, push-button switch, the button "click-click", the button "trigger-release", roller, piston, mouse, light pen, keyboard, sensitive area of the monitor screen.
The keyboard is the key layout (block or functional) way. Types of keyboards:
1. Numeric keypad - the set of keys marked with numbers.
2. Alphanumeric keyboard - set of keys, denoted by the set of symbols;
Examples: letters of the alphabet (A through Z); numerals (0 through 9); non-printable space character; punctuation marks, and other graphics, if needed.
3. functional keypad: a Set keys, representing some equipment, machines, functions, or commands.
Human machine interface (HMI) is a set of technical means designed to ensure direct interaction between operator and equipment, which allows the operator to control the equipment and monitor its operation.
Note: Such means may include manually operated controls, the control device displays.
Human-machine interfaces are divided into:
Hardware interfaces;
Programming interfaces(user interface);
Hardware-software interfaces.
The signal is visual, audio or tactile marking of the transmitted information. Types of signals:
1. a visual signal, a visual marking of the transmitted information by means of signs, shapes, colors, and other display information.
2. beep - audible designation of information to be transmitted by means of tone, frequency or periodicity.
3. tactile signal - feel the designation (through the tactile senses of the person) of the transmitted information by means of surface roughness, contours or special placement of the control.
Peripherals (VDT) - equipment with which users interact with the system. This definition includes both the monitor (VDU) (output information) and the device information input into the computer system (usually the keyboard). The definition also refers to any other electronic equipment (e.g. mouse, digitizer, trackball) required for operation of the system.
Duchainify controller (VDU controller) is a specialized manipulator designed to select a specific area on the output device, which represents some of the equipment or device to issue a command.
Note – two-coordinate controller can be a joystick, mouse, trackball, digitizer, touch panel screens are active.
The basic principles of human-machine interfaces
The application of the principles of actuation, structural location and sequence of operation of controls shall be considered in the development stage and the design of the equipment.
Type, form and size on the control and its location should be chosen in such a way that it meets the requirements of the assignment, maintenance and operating conditions. Should also be taken into account the skills of users, limitations in maneuverability, aspects of ergonomics and the required level of preventing inadvertent execution of the operation.
The principles of the HMI:
1. The controls shall be clearly identified in all of these States and are strategically placed to allow safe and timely execution of operations.
2. The management body needs to perform only commands matching the specified purposes of its use.
3. User actions must not lead to uncertain or dangerous condition of the equipment or process.
4. The controls and related control devices shall be placed in accordance with the requirements of industry regulations, DSTU, GOST and international standards and to be functionally interrelated.
5. Method of dialogue used in the HMI must take into account aspects of ergonomics specific to a given task.
6. To reduce the risk of impacts associated with human errors, it is recommended to provide:
- a certain priority of commands (for example, the command "STOP" has a higher priority than the command "START");
- simplification of the sequence of operation of the management body (such as through automation);
- lock management (for example, two hands);
- running in jog mode.
7. Controls should be logically grouped according to their operational or functional relationship necessary to ensure the control equipment. This principle must be respected in all areas of application.
The control layout should be designed to facilitate its identification and to minimize the probability of an incorrect actuation, which is the result of operator error.
Should be used one or more of the following principles of grouping the controls:
- grouping by functions or relations;
- grouping by sequence of use;
- grouping by frequency of use;
- group by priority;
- grouping procedures for the operation (normal or critical);
- grouping by modeling the schema of the enterprise (the machine).
The principles of grouping should be consistent with the skills acquired as a result of training.
Should not be used the mirror and the symmetric circuits of the panels located on the controls, controllers and renderers information.
Related groups of controls shall be placed according to their priority level, for example:
- the highest priority – at the top left;
- the lowest priority at the bottom right.