The Electric Workforce

The market for personal and home robotics is on the rise. Precedence Research estimates that the household robot market reached US$12.18 billion in 2024 and forecasts a compound annual growth rate (CAGR) of 19.32 percent through 2034 to reach US$71.26 billion¹. To meet the needs of this market, designers are leveraging advances in batteries, power management, wired and wireless connectivity, sensor fusion, and real-time processing to ensure safe and reliable performance.

However, designers face challenges in building personal and home robots. These robots may need to be capable of autonomous mapping and developing efficient, safe routes to complete their tasks while optimizing battery life. They may also need to interact with humans; options include voice commands, front-panel touchscreen controls, or an app.

To ensure proper operation and to facilitate mapping and navigation, personal and home robots may employ a variety of sensors. Most robots will include battery monitors that measure the state of charge, and most will include Hall-effect sensors to monitor motor operation and temperature sensors to shut them down if an overload condition occurs. Other common sensors include inertial measurement units (IMUs) that keep the robots steady by providing feedback on acceleration and rotation.

Object recognition and avoidance are key requirements for home and personal robots, and many will employ lidar, vision, infrared (IR), ultrasonic, or some combination of these sensors. These same sensors can help a home or personal robot plan optimum routes for tasks like delivering food, cleaning all pool segments, or mowing all parts of the lawn. Finally, home and personal robots will require microphones, touchscreens, or RF connectivity to communicate with humans.

This article presents three examples of personal and home robotics applications and describes the importance interconnects play in robotics designs.

Robotic Restaurant Server

Robotic servers are becoming increasingly attractive to restaurant owners because of labor shortages and rising costs. The current generation of robotic servers does not replace humans; instead, they assist in arduous tasks such as running food and bussing dishware². Restaurant robot servers require precise obstacle detection sensors to help them navigate crowded and unpredictable restaurant environments. Most server robots use a combination of lidar and cameras to build a 3D map of their surroundings with object detection. They must also have a human-machine interface (HMI) that is intuitive for both restaurant employees and guests. The HMI could be any combination of a touch screen, voice recognition, and an app. Engineers must balance performance and reliability with cost-effectiveness to make robot servers an attractive investment for the restaurant industry.

Figure 1 shows a teardown of a robotic server, detailing the variety of data and power connections. The robot moves around the restaurant with onboard battery-powered motors. The battery can be charged from a wall outlet or a charging dock. Hot-swappable batteries enable robots to run continuously with no downtime for charging. Connectors in the battery management system (BMS) and drivetrain must be vibration-resistant and ruggedized to protect users and the robot from spills.

The robot also needs wide-bandwidth data connectors for sensors and onboard electronics. Data from lidar and cameras must be processed quickly to enable the robot to react to its surroundings in real time and avoid collisions. Flexible-printed-circuit (FPC) and flexible-flat-connector (FFC) interconnects provide options for routing signals and low voltages through space-constrained robot housings. The robot must also contain the respective RF circuitry for Wi-Fi or Bluetooth^® if the HMI includes wireless connectivity.

Robotic Pool Cleaner

Another example of service robotics is the robotic pool cleaner (Figure 2). Such robots have a variety of sensors to help them navigate the pool, deftly managing floors, walls, and steps while avoiding ladders and other obstacles. Pool-cleaning robots may use cameras, often complemented with water-pressure sensors, which provide depth information to aid in navigation, and ultrasonic sensors, which provide distance measurements to help plot an optimal path for thoroughly cleaning the pool in the shortest amount of time. The robot may also employ flow sensors to ensure proper suction and water flow through filters, as well as tilt sensors to determine if it has flipped over so it can initiate corrective action.

A pool-cleaning robot will have some medium-power connectors that route low-voltage power to its battery and many actuators, including rubber wheels or tracks. The wheels or tracks may be augmented by water jets or even small propellers to assist in precise navigation.

To recharge the battery, users will typically need to remove the robot from the pool and connect it to a wall power outlet using an adapter, such as a USB Power Delivery adapter with a USB Type-C connector. When detecting a low battery, some sophisticated pool robots will navigate to a poolside recharging station, which, in some cases, can be solar powered.

Robotic Lawn Mower

One of the many sensors that robotic lawn mowers might use—and one that robotic servers and pool cleaners would not—is a boundary-wire detector. For this type of robot, the user must install a boundary wire around the perimeter of the lawn to be mowed so the robot will stay within the delineated area. Alternatively, the mower could use a real-time kinematics (RTK) reference station, which enables enhanced global positioning system (GPS) navigation. Another option is to equip the mower with lidar sensors, enabling it to build a 3D point map to stay within the property limits. With RTK and lidar approaches, the user must train the robot initially by manually operating it around the perimeter via remote control.

Robotic lawn mowers may include ultrasonic sensors, which can help the robot avoid collisions, and tilt sensors, which allow the mower to stop the blade if it is lifted or tilted. In addition, a moisture sensor can signal the robot to return to its charging station in the event of rain, while a pressure sensor might detect when the grass bag is full.

Users can interact with the robotic lawn mower using a wireless app or a front panel touchscreen, such as one implemented using a Molex PEDOT clear conductive sensor (Figure 3), which enables the fabrication of backlit capacitive touch-panel user interfaces on curved surfaces³. These sensors incorporate poly (3,4-ethylenedioxythiophene), known as PEDOT, an organic polymer that offers several advantages for capacitive touch switches. PEDOT combines conductivity and transparency, can be deposited onto inexpensive polyester film in an additive process, and lets designers leverage recent progress in the field of low-temperature soldering.

With such a touchscreen interface, users can issue simple start and stop commands to the robot, schedule mowing times, and program cutting height and mowing patterns.

The Role of Connectivity

Critical to robotics are the connectors and cable assemblies that carry signals and power. These connectors and assemblies include high-power versions that carry power from the grid or even local renewable sources such as solar panels to the robot's battery by way of an onboard or remote charger. Other connectors carry data from sensors to printed circuit board (PCB)-mounted microcontrollers and other integrated circuits (ICs) that make decisions regarding navigation, power management, and other functions. Others carry power between the PCBs and actuators that put the robot in motion. Most robots also include RF connectors that help establish cellular, Wi-Fi, or other wireless communication links. All these connectors must be reliable, compact, and easy to install during manufacturing.

Conclusion

Personal and home robots can assist humans in tasks such as serving meals, cleaning pools, and mowing lawns. The underlying technologies—chargers, sensors, processors, and actuators—require effective, reliable interconnect components and assemblies to carry power and signal throughout each robot. Molex offers a comprehensive line of standard and custom interconnect products ranging from high-power connectors to RF cable assemblies operating at frequencies up to 110 GHz. Molex has engineered these products to facilitate manufacturing and ensure reliability throughout the robot's life cycle. 

¹https://www.precedenceresearch.com/household-robots-market

²https://backofhouse.io/resources/how-do-robotic-waiters-work-and-are-they-right-for-your-restaurant

³https://www.molex.com/en-us/blog/how-pedot-is-revolutionizing-touch-switches

Access to data is not the sole reason farming is following other industries' technology use; robots and intelligent agricultural machines are automating the laborious tasks of seeding, planting, weeding, and harvesting crops. In dairy and livestock husbandry, Internet of Things (IoT) sensors and smart tags attached to animals help monitor their health, the need for supplements, and optimal diet.

However, deploying any form of technology outdoors presents a set of unique challenges. The weather is the most significant of these. Machines are required to function in all types of weather conditions, such as freezing snow, blistering heat, and strong winds.

Environmental Challenges

Weather heavily influences a machine's working conditions. Prolonged heavy rain can turn even the most compacted soil into a glutinous sea of mud, trapping machines and disrupting schedules. High winds can whip up dry sandy soil into an abrasive dust cloud that's likely to damage sensors, clog gearboxes, and penetrate seals of control equipment that is not suitably protected.

Ingress protection of control electronics is paramount. The equipment's operating specification should stipulate the required ingress protection (IP) rating. The IP rating consists of two numbers—the first indicating the protection rating against solid objects like dust and the second indicating the protection against liquids—with the highest possible rating of IP69 (Figure 1).

Ingress Protection (IP) Ratings Guide

IP requirements go beyond the machine's operational environment. On a typical working day, any item of machinery can become caked in mud and covered in dust, and pressure washing is often the preferred method of cleaning. High-pressure jets can quickly force water past seals and penetrate connectors.

Building operational endurance and resilience into a product also requires understanding the mechanical stresses the machine may encounter during use, such as vibration and torsional forces when moving over hard and rutted soil.

Temperature extremes and long-term exposure to sunlight can also cause rubber and plastic materials to soften, deteriorate, and become brittle, resulting in loss of ingress protection and premature component failure. Engineers should carefully review the long-term effects of exposure for all components and enclosures that will be subjected to the elements.

Other weak points for water and dust ingress include points where sensors, motors, and actuators are connected to control electronics. Any interconnect should feature the same level of ingress protection as the primary enclosure. Likewise, antenna connectors for wireless communication require protection against all the elements.

A popular connector format suitable for agricultural applications is the Molex Squba connector. Designed for rugged environments, these connectors feature an IP68 rating and provide secure, sealed power and signal connectivity. Their latching and lockable design ensures durability against dust, water, and harsh conditions, making them an ideal choice for industrial and agricultural applications.

Technical Considerations

Designing a smart agricultural machine requires a careful analysis of its specific tasks. In addition to the environmental factors previously discussed, several key technical considerations exist.

The machine's role will dictate the type of sensors required; for example, a weeding machine may use cameras to identify the weed from the crop and carefully guide the effectors into the correct position (Figure 2). The camera’s key technical specifications will likely include the resolution, angle of view, refresh rate, and host interface. Other sensor types may stipulate specific environmental parameters, such as the operating temperature range, humidity range, and air pressure limits.

Agricultural robots rely on many sensors, such as cameras, soil monitors, and weather detectors. Sensor fusion allows data from these sources to integrate to help machines make accurate, real-time decisions, such as identifying weeds or adjusting planting depths based on soil conditions.

The machine's use case will also influence the power requirements. Since most smart machines need to be self-powered, this suggests either battery power or, if the machine is sufficiently large, a fuel-powered alternator. Major motive components like motors and actuators will indicate the required power budget. Additionally, engineers need to add the total power consumption of the onboard electronics, sensors, etc. Using battery power alone will limit the machine's endurance capability. Solar panels may assist in charging the batteries during operation, but one should not assume that will be the case. Profiling the machine's energy consumption across a series of use cases and mission parameters will indicate the likely battery sizes required.

The increasing use of machine learning (ML) and artificial intelligence (AI) algorithms may also impact the machine's power requirements since many algorithms may place a heavy and spiking workload on the machine's computing resources.

Wireless connectivity is crucial for virtually every remote application, and multiple antennas and durable connectors are necessary for maintaining link resilience and robustness. Molex offers a comprehensive range of RF connectors that cater to all popular wireless protocols and standards and are available as discrete plugs, sockets, or complete cable assemblies. For example, the Molex 5G25 RF flex-to-board connectors offer high signal integrity performance for applications up to 25GHz.

Smart agricultural machines will experience vibration during movement and operation, so ensuring reliable power and signal connectivity between PCBs, sensors, solar panels, and subsystems is crucial. Molex offers a diverse range of interconnect solutions, including board-to-board, FPC, I/O, RF, and high-power options, all designed to withstand harsh conditions. The ruggedized connectors with high IP ratings ensure durable, secure connections even in harsh agricultural environments.

Deploying Robust and Resilient Smart Agricultural Machines

The development and deployment of intelligent machines are making traditional agricultural practices far more productive and efficient. These machines can work unattended, taking on mundane yet vital tasks such as removing weeds and picking crops, signifying a new farming era.

However, to achieve the desired performance levels, the machines must be sufficiently robust and durable to withstand operation in all types of weather and on unpredictable and changeable surfaces. Engineering teams should carefully analyze the range of environmental conditions a machine might encounter during its operational life, ensuring the selected electronic components and system construction methods meet requirements.

By employing the right design strategies, smart agricultural machines can further change farming practices by maximizing yields while minimizing environmental effects and use of resources.  

¹https://www.statista.com/statistics/720062/market-value-smart-agriculture-worldwide/